Ianto was born in August 1983 the 19th in Cardiff. Few is know about his family. He's got a sister Rhiannon, from whom he seems a little close but also distant (probably because of his job), and we know he grew with his father, who works at Debenhams. Ianto once revealed taht him and his father used to go to cinema.
He loses his father before went off University. Rhiannon, revealed to Gwen that one day, their father broke Ianto's leg, while pushing him on the swings.
Ianto had many tempraries jobs, and ends up as a junior researcher to Torchwood1.
Lanto works as a junior researcher to Torchwood 1 in Canary Wharf, London; There he met his girlfriend, Lisa Hallett. But during the Canary Wharf battle with the cybermen, Lisa is captured and transformed into a Cyberwoman. Torchwood 1 is destroyed and Ianto asks Captain Jack Harkness to joins Torchwood 3.
In the first episode of season 1, Ianto is introduced to Gwen Cooper as the cleaner and the tea boy. He's the one in the team who cleans everything after torchwood's passage (dispose of bodies, erase of evry alien stuff...).
He has a small role in the next episods until the number four: Cyberwoman.
In the "Cyberwoman" episod, it is revealed that Ianto's girlfriend, Lisa, has been turned into a cyberwoman, but just partially. Hoping to reverse the effect of the transmutation, Ianto keeps her on the subbasement of Torchwood. When he tries to reverse it with the help of a chinese doctor, Lisa seems to go back to normal. Nonetheless, the cyberwoman side cames back, she kills the doctor and tries to transformed Gwen into a cyberwomen.
Ianto still believes Lisa's soul still there and tries to talk to her, but Lisa knocks him out and then threats the rest of the
team. While Owen and Gwen hide in a cold chamber, and Tosh tries to repowered up the basement, Jack tries to wake up Ianto and kisses him.
After everybody's escape from the hub, Jack aim to Ianto and threatens him to shoot him if he refused to killed Lisa. Ianto goes down to the hub to find Lisa's body, and the pizza girl with Lisa's soul. "Lisa" tells to Ianto all her memories and Ianto can't kill her, she then said that she could make them perfect, before being shot by Jack.
Ianto then said to Jack that one day Jack will gonna need some help, but he will look him die.
The next morning, Ianto came back to the hub, look at to Jack and then go back to his work.
In the next episod, "Small Worlds", Jack wakes up after a nightmare and find Ianto in the hub. He then asks Ianto what is he doing here, putting his hand on Ianto's shoulder. Ianto then looks at him a little tense, perhaps because he's still mad about Lisa's story or because he starts to fell attracted to him or the both...
In "Countrycide" Ianto is seen for the first time in casual clothes, not in a suit. He goes on the field with the team for the first time. Gwen starts the game "who's the last person you've kissed", when it cames to Ianto's turn, he said it was Lisa, putting a little tension in the team, then looking to Jack (Because he still angry at or/and knows that Jack kissed him).
After losing their car, the team is lead to a small creepy village. There Ianto and Tosh are held captive in a subbasement. They discovered a fridge full of human meat. Then Ianto said to Tosh that he hates, the look they've got when they are in danger and the fact they liked it. After being taken by Helen for the harvest, Ianto bravely attacks Helen and her husband to allows Toshiko to escape. When Tosh, Owen and Gwen are captured again, they find Ianto still alive. Then Eavn takes Ianto in the goal to cut his throat , but Jack arrives and saves his teamworkers.
In " Greeks Bearing Gifts", Toshiko could reads in people'smind, and then she sees all Ianto's pain and grief since he had loose Lisa.
In "They keep Killing Suzie" The team must brought back to life their former co-worker Suzie Costello with the resurection gauntlet. Owen said that they never find a cool name for the artefact and then Ianto suggest the Risen Mitten. When they used again the knife, Owen looks at Ianto for a nickname and the last one said the Life Knife. After Suzie being resurected, she escapes with an unwell -being Gwen and locks up torchwood in the hub with no communication. Ianto then used the waterfill to have some network for the cellphone. After killing Suzie again, Ianto puts her body back to the cold storage, and then flirts with Jack, supposing the two became sexually involved...
In the next episods Ianto is a support to the team for the investigation in "Random Shoes", the reinsertion of the three people lost in time in "Out of time", and helping Owen in "Combat"
In "Captain Jack Harkness", Jack and Toshiko are stuck in 1941, January the 20th due to the rift manipulation of Billis Manger. Owen and Ianto trie to relaunch the rift to get them back but it misses a part of the equation, present on Toshiko's laptop, in 1941. Owen, hoping to retrieve his lost love Diane, wants to trie to open the rift without the complete equation, but Ianto refuses saying it's to dangerous. The two argue, Owen tries tu put the key so Ianto shots him in the shoulder. Thanks to Toshiko genius they succeed to open the rift and get Jack and Tosh back and closed the rift.
In the last episod "End of days", Tosh sees her dead mother, Owen his lost love Diane and Ianto his beloved Lisa, asking them to open the rift one more time. After Rhys is killed by Billis, Gwen, Ianto, Tosh and Owen decide to open the rift, Owen shots Jack who refused to do so(wich upset a little Ianto). After openning the rift, a big sucking life monster called Abadon his unl
eashed. Jack cames back to life, and the team came out of the hub for stopping Abadon. Jack sacrifices himself to kill Abadon. In the cold storage, Gwen refuses to put Jack's body in one of the cave so she waits until Jack cames back to life one more time. Gwen and Jack rejoin the team in the hub. Happy to seein g him back, Ianto goes to Jack but don't know how to express his joy... Jack then hugs him and kisses him. Few minutes later while they are out for some coffee Jack disapears, leaving Ianto and the rest of his team...