Tsumionji

Tsumionji is the femslash ship between Mikan Tsumiki and Hiyoko Saionji from the Danganronpa fandom.

Canon
For most of the game, Hiyoko is abusive towards Mikan, bullying her and calling her names like "pig barf". Mikan never defends herself against the bullying, which in turn enrages Hiyoko and causes her to bully her more.

During the Twilight Murder Syndrome section of Chapter 2, it is revealed Mikan and Hiyoko used to be friends in Hope's Peak, alongside Ibuki Mioda and Mahiru Koizumi, although how their relationship was at this point is not shown.

During Chapter 3 Mikan is reverted to her Ultimate Despair personality and murders Hiyoko when she walks in on her arranging Ibuki's crime scene.

Their relationship appears to be exactly the same during their time at Hope's Peak Academy, as shown in Despair Arc of Danganronpa 3. In the finale, Hope Arc, Mikan saves Hiyoko from a brainwashed task force member. The latter asks her what took her so long, but then reluctantly, although sincerely, thanks her, causing Mikan to cry in joy. This implies that Hiyoko forgave Mikan killing her during the Killing School Trip.

In the non-canon "Danganronpa V3" bonus mode Ultimate Talent Development Plan, Hiyoko decided to meet up with Mikan in the nurse office since she was in a bad mood. Mikan was surprised and curious how Hiyoko would meet up with her. Mikan then smiled that Hiyoko came to be friends with her and chat along which Hiyoko declines, telling her to not smile. In the end, Hiyoko states how she forgot about her nervousness when she talked with Mikan.

Fanon
Hiyoko's insults towards Mikan are usually aimed towards her body, such as calling her a slut for landing in unusual compromising positions. This may indicate Hiyoko having some sort of attraction towards her which she covers up with bullying.

Although manga adaptations aren't exactly canon, one of them has Hiyoko be aware of Mikan's mentality where the latter believes it's better to be bullied than ignored or forgotten, implying Hiyoko might be bullying Mikan because she still finds it better than no one paying attention to her. However, whether that was the nature of their relationship in canon is up to the reader's interpratation.

Fandom
FAN FICTION

Trivia

 * This is one of several ships between a victim and their killer, with the others being Leosaya, Chimondo, Yamaceles, Mahpeko, Band Aid, Nekodam, Komanami, Nishichino, Amamatsu, Shiromami, Toshi, Shinnaga, and Oumota.
 * This is also one of two ships between a victim and a culprit of Danganronpa 2's Chapter 3, with the other being Band Aid.