Yukiteru has a very feeble personality. He is polite, quiet, kind, apologetic, and shy, and is well-intentioned, but also very self-defeating: he lacks judgement and is totally incapable of standing his ground, always "going with the flow" of other peoples interests. His kindness to satisfy people is ultimately his weakness: leading him into a lot of trouble throughout the series.
His self-defeating personality is twisted in other ways. As a child (chapter 1), he accidentally knocked the candle in the loft of his home, causing it to burn down, and he thought the burning was "pretty". Also, in general he is attracted to Rena more and is scared of Yuno, but after the events at the theme park with Rena and Yuno (chapter 6), he says the "pain" of cheating feels "delighting".
He is also very perverted and too easily aroused, and enjoys (when the hidden opportunity allows) sexual activity with girls, in particular Rena. He knows he shouldn't have sex with other girls, but as he is so easily turned on he hasn't the strength to refuse the opportunity offered and still enjoys the physical activity. He is prone to ejaculating quickly, and it is visible he generates extremely large amounts of semen (a.k.a. "cum").
Yukiteru calls Yuno by her first name, but everyone else by their surname.
Yuno vs RenaEdit
In essence, because Yuno has been so possessive of Yukiteru, and because Yuno can be mentally unstable, Yukiteru seems to have developed an instinct to "survive", as a result of Yuno's persistence and because the two have known each other for so long. In his mental monologues throughout the story, he says he "likes" Yuno (quotation marks are explicitly used), to seemingly hint he likes her as a family friend, but does not truly love her in an affectionate way (in the manga, sometimes dubbed "like-like"). In dialogues with her, he has developed an automatic response to Yuno's emotions by saying he "loves" her - probably in case she breaks down and goes psychopathic, but certainly because he doesn't want to disappoint or hurt her.
As a teenager, when he first saw Rena he felt different; actually saying in a monologue he has intense feelings for her and it's the first time he has truely "liked" (loved) another person, supported by his urge to masturbate while thinking about her. This is probably why he can easily have sex with Rena, but not with Yuno. When he attempts to refuse joining the SF club with Alice, it is because he thinks of Rena's misery after the summer incident, and he explicitly says to Alice that there is someone he likes.
In short: beyond his meeting with Rena and their first time having sex, he is mentally torn. He likes Yuno as a friend, but is pressurized into loving her, while he seems to really love Rena since he is more easily turned on by her and enjoys the pleasure she has to offer, but is forbidden from really falling in love with her since Yuno will unstabilize. Yuno is "Yandere" in relation to Yukiteru.
Hobbies and interestsEdit
None are currently known. He appears to be very passive and inactive; shown only sitting, standing, or walking around.
Yukiteru is a fairly tall and very slim teenager, with black spikey hair brushed downwards, and brown eyes. Most of the time he is seen in plain and simple trousers and tops, or school uniform.
The incredibly tense situations he gets himself into, and his regretful decisions, mean he is exclusively seen with a depressed, stressed out, or panicked look, aside from the one-off occasions when he can be happy suggesting a playful side.
Only his parents have briefly been revealed in the flashbacks, nothing more is known about them. So far he has no known siblings. He has two known children, one with Yuno and Rena, though he never met either as they were born after his death,
Yukituru was murdered by a killer who pushes him into an oncoming train at a station.