In Chapter 3 of Danganronpa: Trigger Happy Havoc, the remaining students discover a laptop inside of a locker in the Bathhouse. They had found that installed into the laptop was an artificial intelligence named Alter Ego, who was created by the recently deceased Chihiro Fujisaki. Hifumi does not attempt to hide his fixation on the AI, and openly expresses his enticement in how Alter Ego says the word "Master." When Yasuhiro Hagakure brings up how he thought that Hifumi was only into 2D, Hifumi proclaims that Alter Ego is the most excellent 2D possible, and is also unbothered by how it was only a computer program, and that it resembled its creator, who was male. When Alter Ego is saddened after learning that their creator had been killed by Mondo Owada, Hifumi expresses sympathy for him, and even questions Celestia Ludenberg's statement that a computer program does not have feelings. When the group leaves, Hifumi promises Alter Ego that they'll come back.
Later on, Kyoko Kirigiri had discovered that Hifumi had accessed Alter Ego without permission, and found him hugging the laptop while breathing heavily. When Makoto Naegi asks him what had happened, Hifumi explains that they were only talking, and eventually admits to falling in love with the AI. Originally he had just wanted to hear them say "Master" one more time, but became intrigued by what a well-designed program it was. He then describes Alter Ego as being the first "girl" whom he felt comfortable speaking with, because they were not at all annoyed or disgusted by his hobbies. Celestia then tells Hifumi that he is misunderstanding the situation, and that Alter Ego wasn't interested in him, but rather the things that he knew, because an AI exists to learn as much information as possible. Suddenly, Kiyotaka Ishimaru rushes into the room, and tells Hifumi that Alter Ego belongs to him, as it helped him regain his spirit after the death of his close friend, Mondo. Hifumi tells him that he can't allow that, and an intense dispute arises between the two. Kyoko manages to stop their feud, and tells them both that Alter Ego belongs to no one.
Later on in the chapter, the group finds that Alter Ego had been stolen from the locker, and Hifumi accuses Kiyotaka of taking them. Kiyotaka denies this, and then accuses Hifumi of being the culprit, which he also denies. Hifumi begs for somebody to rescue her, and says that he just wants to see their smiling face again. Kyoko reassures that Alter Ego is most likely safe, and Hifumi proclaims that he will save her using the power of love. The group then heads off to bed, with both Hifumi and Kiyotaka still concerned for the well-being of the AI.
After the Class Trial, Celestia reveals that she was able to convince Hifumi to help carry out her scheme by making him believe that Kiyotaka was the one who had stolen Alter Ego, and that he planned on killing Hifumi so that he could keep them to himself. This enraged Hifumi, who would end up killing Kiyotaka, before he himself was subsequently betrayed and murdered by Celestia.
In Chapter 4, when the remaining students are conversing with Alter Ego, the AI expresses sadness over the absence of Hifumi, as well as Celestia and Kiyotaka, as he considered all of them to be his friends.
Naturally, the ship is not popular within the fandom, as most Hifumi ships tend to be unpopular, while Alter Ego is not commonly shipped with any character at all. What is somewhat surprising is that the ship actually has a rival, as some prefer the bond between Alter Ego and Kiyotaka, though the latter ship is also fairly overlooked by the fandom.
- Alter Ego is one of two love interests of Hifumi, the other being the fictional anime character, Princess Piggles from Demon Angel☆Pretty Pudgy Princess.