Continuing from the last volume; Naru has just told Keitaro and Mutsumi that they are the two who made the promise to each other. Naru tells them she's happy for them, and runs off crying. Mutsumi doesn't quite understand what's going on. Keitaro grabs her hand and goes chasing after Naru. He finds the picture Naru had discovered of him and Mutsumi playing in a sandbox when they were little.
Naru has stopped and is wondering if she did the right thing. Keitaro comes running up; holding Mutsumi's hand. Keitaro stops Naru from running off again, and she yells at him. Keitaro tells her he may have made his promise to Mutsumi, but he cares about both of them. He doesn't want to let her go.
A short time later, the three of them are at a restaurant. Keitaro is still holding onto both of their hands. Naru screams about how stupid the situation is, but Keitaro tells her he's confused and he needs more time. Naru gives him until they get back to Hinata House to make a decision. The three of them go walking back to Hinata House. Keitaro agonizes over his decision and has visions of multiple-choice tests running through his head.
Finally, the moment of truth has arrived. They climb the steps to Hinata House. Naru is still holding Keitaro's hand, and she thinks he might have chose her, but... Keitaro is still holding BOTH of their hands. Keitaro says that whenever he doesn't know the answer on an exam, he leaves it blank. Mutsumi says to let it slide, because there's no comparison between exams and love. Naru angrily tells her that's easy for her to say; Mutsumi was the one kissing him. Mutsumi grabs Naru's head and makes her kiss Keitaro so they'll be even. They decide to drop Keitaro and go have fun at the Christmas party.
Hinata House is celebrating New Year's, when they notice smoke coming from Mutsumi's apartment. They go to investigate and find that Mutsumi's okay. Her hot water heater exploded, and now all she has left is her exam ticket and the clothes on her back. Mutsumi intends to go back to Okinawa, but Keitaro convinces her to go to a temple and get her luck cleansed.
They go to the temple and make their wishes. Shinobu wants to draw their luck, despite Sarah's warnings that they know how it'll end. Mutsumi draws "Worst Luck", but Keitaro says he knows who can cleanse it: Motoko.
Meanwhile, Motoko is in the temple and is disturbed that her fortune mentioned love on the horizon. The gang arrives, and Motoko agrees to perform a purification ceremony. During the ceremony, Motoko is surprised to learn that somebody as unlucky as Mutsumi is protected by a goddess. Motoko realizes that KEITARO is the one who needs to be cleansed, as he is projecting his bad luck onto Mutsumi and Naru.
She charges Keitaro with her sword to perform the ceremony, and Keitaro runs away in fright. Naru and Mutsumi grab each of his arms, and Motoko uses the Cutting Evil Strike!! Second Form!!. Unfortunately, instead of cleansing Keitaro of evil, it only cuts Naru's and Mutsumi's clothes. Motoko surmises that when the three of them are together; the misfortune is just too strong.
Back at Hinata House, Haruka has decided to let Mutsumi stay at Hinata House in exchange for helping out at the cafe.
The center exams are set to begin and Keitaro is freaking out. As is usual, he gets very nervous and starts making lots of stupid mistakes. Afterwards, he is stopped and interviewed by a TV reporter. He claims to think he passed, but really he's scared about being a fourth year ronin. Later, back at Hinata House, Naru and Mutsumi ask him if he really thinks he passed. Keitaro lies and says yes. They decide to go ice skating to unwind from the day's stress.
Naru and Mutsumi are having a good time, but Keitaro is too preoccupied. He apologizes for being such a loser, and skates off. He runs into Seta and Sarah, who are ice fishing. Seta asks him what's wrong, and Keitaro tells him. Seta tells him to have fun and be more confident in his decisions. Besides, if he fails he can alway come to work for Seta. Keitaro shares some of Seta's fish and agrees that he's right. He plans to go apologize to Naru for lying, but she overhears him anyway. Naru thumps him and tells him that as close as they are; he should be able to be honest with her.
They score Keitaro's test, and are shocked to find out that he did better than she did!
Naru and Mutsumi are relaxing in the hot springs, when Sarah and Su come charging, too. They see Keitaro walking past the screen, and Naru gets ready to pound him. To everyone's amazement, he just walks on by.
Keitaro is revealed to be deep in study. Sarah and Su run out of the bath, preparing to jump him. They're surprised when Keitaro dodges their attack. Keitaro sees them and asks them if they needed anything. Su tells him no, and to just do his best.
The two girls run and tell Kitsune and Shinobu that something horrible has happened to Keitaro. Kitsune and Shinobu don't believe them, until they see Keitaro walk past Naru without slipping on a banana peel that was on the floor. Later, he manages to save Motoko from freaking out about Tama-chan, and is seemingly immune to Kitsune's attempts to seduce him. Motoko and Kitsune both seem to prefer the "new" Keitaro, while the younger residents prefer the old.
Shinobu tells Naru that Keitaro is acting strangely. Naru doubts her and tells her that Keitaro is a pervert through-and through. Later, she and Keitaro are studying together and she realizes how focused he seems. She decides to get his attention by showing some skin, but he ignores her. Naru starts to worry that he's lost interest in her.
All of the female residents get together in the hot springs and discuss the new Keitaro. Suddenly, Keitaro comes bursting in, and tells Naru that he finally figured out the solution to the math problem he had been working on. She congratulates him, and then realizes that this was the reason he's been acting so strangely. Then it hits her that the old Keitaro is back and he's in the bath with them. The ladies attack, and everything is back to normal.
Keitaro and Naru come stumbling downstairs after a hard night of studying, and they look like crap. Mutsumi enters; looking chipper as usual. Mutsumi asks Keitaro if he'll go on a date with her. Naru asks her how can she think of dating with their exams coming up. Mutsumi then asks Keitaro if he'll go looking for a reference book with her. He asks Naru if it's okay, and she tells him to do whatever he wants.
Keitaro meets Mutsumi in the same place he had met Naru on THEIR date. They go to the bookstore, and Keitaro plans to tell Mutsumi that even if she is the girl he made is his promise to; he has feelings for Naru. While Keitaro is making his plans, it is revealed that Naru is spying on him and Mutsumi. She runs into Su, begs her not to tell anyone. Su agrees to help her spy.
Keitaro and Mutsumi go to a ramen shop, with Keitaro and Su following behind. Su unveils her latest invention: the Mecha Tama-chan Mark III. This is a reconnaissance turtle, and she replaces the real Tama-chan with her mecha. As they leave the ramen shop, Keitaro notices that Tama-chan feels much heavier.
Various hijinks ensue, and Keitaro and Mutsumi end up on boat. Keitaro is frustrated because he was trying to not seem like a couple. Mutsumi lays Keitaro's head on her lap, and realizes there's no way he can tell her about his feelings for Naru right now. Meanwhile, Naru is becoming increasingly agitated. When Mutsumi leans forward and looks like she is going to kiss Keitaro, Naru grabs the MT3's control and accidentally arms it's warhead; blowing everyone out of the water.
Back on land, Mutsumi asks Naru what she and Su were doing out on the water. Naru gets flustered, but Su covers and says Naru is trying to hide the fact that they're lovers. As Naru chases after Su, Mutsumi tells Keitaro that she wishes he was the one she had made her promise to.
Naru walks in on Keitaro in the kitchen, and she thinks he's pulling an all-nighter. Then she realizes that he's actually baking his annual Valentine's Day pity-cake. Disgusted, she tells him he lives in a girls dorm now. It's not like he won't get any chocolate. He tells her that it's a ritual for him and asks her if she's going to give him chocolate this year. She rudely tells him no, and he goes off to bed. Naru glances at the baking equipment he'd left out, and decides she'll bake something before anybody walks in. Unfortunately, Kitsune and Sarah walk in, but Naru manages to convince them she's just making a midnight snack.
The next day, Shinobu is the first one to give Keitaro chocolate. She's followed by Su's curry-choco, and then Motoko actually gives Keitaro a box of chocolates this time. Naru watches Kitsune and Sarah give him their chocolate, and she gets frustrated because her's didn't turn out well. She decides to hide her chocolate, and justifies it by figuring it wouldn't be fair to Mutsumi, anyways. Mutsumi enters and asks Naru if she was planning on giving any choco to Keitaro. Naru tells her that she doesn't have time for stuff like that, and Mutsumi wonders if she shouldn't give Keitaro her chocolate then. Naru asks Mutsumi where her chocolate is, when a chocolate cake goes literally flying by. Mutsumi had enveloped Tama-chan in a block of chocolate! She then reveals her real cake. Keitaro enters and admires Mutsumi's choco. He again asks Naru if she was going to give him any chocolate. She yells at him and storms off.
Deciding that there's no way she can give him her chocolate now, Naru goes to throw her culinary abomination away. She opens the cabinet door, but it's empty. Her choco is gone. She sees Tama-chan flying by with the chocolate on it's back. She chases after the flying turtle and manages to catch her, but not before running into Keitaro. Keitaro opens the box and unveils the chocolate that Naru had been trying to hide. It's...kind of odd-looking. At first Keitaro thinks it's some kind of avant-garde art. He then realizes that it's chocolate, and Naru must have made it. He takes a bite and tells her that it was the best he had all day.
Later that night, Haruka tells Naru that they repainted Mutsumi's room and tells her that Mutsumi needs to sleep with her tonight. As they're preparing for bed, Naru and Mutsumi talk about their feelings for Keitaro, and both pinky swear to postpone any advances until after the exams.
The next morning, Naru is woken up by a scream coming from Keitaro's room. She looks through the hole in her floor, and to her horror, sees a naked Mutsumi in the futon with Keitaro.
The other residents have heard Keitaro's scream and they rush to his room. Mutsumi leaves, and tells Keitaro that "last night was a bit painful". Keitaro tries to tell everyone that he has no idea what happened. Kitsune tells Keitaro that he has to take responsibility for his actions and puts him on a mock trial. Things don't go so well for him, when Mutsumi comes back into the room and tells Keitaro that "her test came back positive". Naru knocks Keitaro into the stratosphere and goes running out of the house.
She calms down for a moment and then realizes that Mutsumi wouldn't know she was pregnant so quickly. She talks to Haruka, who tells her that Mutsumi has a bad habit of sleepwalking. Naru concludes that Mutsumi must have been sleepwalking and fell down the hole in her floor. She goes to apologize to Keitaro.
Meanwhile, Keitaro is walking through the city, wondering what he's going to do, and what really happened the night before. He imagines what life would be like married to Mutsumi and is embarrassed when Naru and Mutsumi show up. They tell him about Mutsumi's sleepwalking. Keitaro admits that he's a little disappointed that nothing happened, and Naru chases him.
On the way back to Hinata House they stop and admire the cherry blossoms. Staring at Naru and Keitaro amidst all the blossoms causes something to click in Mutsumi's head. She excitedly tells the other two that she remembers something about the person with whom she made her promise, but she wants to keep it to herself until after the exams. As she runs off, Keitaro and Naru wonder about what they're going to do now. Naru tells him that he'll still be her friend, even after they get into Tokyo U. Keitaro attempts to tell her that he loves her, but she stops him by giving him a kiss. She tells him that it was for luck and runs away.
It's the day before exams start, and Keitaro and Naru are each pondering their future. Keitaro goes out for a walk, and Naru sees him and wishes him luck. He tries to tell her something, but she leaves in a hurry. The next day the gang gathers and wishes them luck.
It's now the first day of the second exam. Naru and Mutsumi meet at Tokyo University. Keitaro comes walking up, and he looks very determined. He tells Mutsumi that he has very important to say to her. He apologizes, and tells her that he can't keep his promise to her anymore. He's found someone else. Mutsumi asks him what he's talking about. Keitaro is puzzled, and Mutsumi tells him that she was not the one he made the promise to. She made her promise to a girl.... Naru. Keitaro and Naru are totally confused. Mutsumi tells Keitaro that the girl he made his promise to was his first love, but she was so young that she didn't remember making a promise. Before she go any further, the bell rings and she runs off to her class.
Keitaro and Naru rush to their class, neither one is sure what to make of this new information. They end up having to sit next to each other, and Keitaro tells her to calm down; everything will be okay. She becomes embarrassed and punches him. The teacher tells her to refrain from killing her fellow students until after the exam. Naru is mortified, but then she looks over and tells Keitaro that she's not so nervous anymore.
The chapter begins with a flashback to Keitaro, Naru, and Mutsumi as children. Mu-chan tells Kei-kun the Tokyo U. fairy tale and asks him if he likes Na-chan. She then tells him to repeat the story to Na-chan, but the flashback ends before that happens.
Back in the present day, Keitaro and Naru leave the party the gang has thrown for them, and go to their rooms for some last minute studying. Naru has trouble sleeping, so she drops through the hole in her floor to talk to Keitaro. She tells him that the very first word that she learned was "Tokyo U". She had picked it somewhere while on vacation with her parents. She tells Keitaro that maybe SHE was the one he promised to. Keitaro reminds her that she denied the same thing when he brought it up last year. She tells him that she would only have been two years old, and wouldn't remember something like that. She then confides in Keitaro that she hasn't hated him as much as she used to. They almost kiss, but instead bump heads. She gives him small kiss on the cheek, and tells him to do his best tomorrow.
This is it... the final day of exams. Keitaro begins his exam. He realizes that he actually understands the questions, and gets excited. Unfortunately, he starts to daydream. In his dreams he passes the Tokyo U exam, and defeats Seta for the right to marry Naru. Suddenly, he is awakened by the test monitor's voice. There's only five minutes left, and Keitaro's mind rips as he realizes that he hasn't even begun the test.
The volume ends with Naru and Mutsumi entering Keitaro's classroom looking for him, only to find it empty. Mutsumi notices a paper on Keitaro's desk.
- Chapter 52: A Little Lost Sheep On A Holy Night?!
- Chapter 53: The Heart-Pounding Bad Luck Cleansing Scheme?!
- Chapter 54: Love Confession On Ice?!
- Chapter 55: That Serious Guy Is A Criminal?!
- Chapter 56: Palpitations on the Love Love Boat
- Chapter 57: Sweet Cho-co-late
- Chapter 58: My Papa Is A Ronin Stone?!
- Chapter 59: Please Don't Say Those Words
- Chapter 60: A Happy End With You