MatsuShima

MatsuShima is the het ship between Yasuke Matsuda and Junko Enoshima.

Canon
Yasuke and Junko were childhood friends and met on amicable terms during when Yasuke's unnamed mother was struck with a disease implied to be Alzheimer's, causing her to lose recognition of her son which also resulted in Yasuke being neglected and abused as a child, which later made him become majorly depressed and introverted before he met Junko while still in elementary school. One particular moment between the two when they were children was when Junko spent many days building a sand castle. One day, the sand castle was found destroyed. Yasuke went around angrily looking for the perpetrator until finally, Junko approached him that it was actually her that destroyed her own sand castle.

In the years following the death of Yasuke's mother, Junko became the person that Yasuke felt he could always lean on, in fact he didn't have any other close ones. She promised to always be there for him, which helped develop his stronger feelings towards her. She said she'll never forget Yasuke even if she forgets everything else, and that they'll always be together. For the first time in his life, Yasuke cried in front of another person, after making her promise she won't make fun of him, won't tell anyone and won't try to console him. He became dependent of her and ready to do anything for her and they eventually became lovers.

Both of them later enrolled in Hope's Peak Academy and after the school's tragedy Yasuke reluctantly assisted Junko in her plans, creating her alternative identity Ryōko Otonashi. He wanted to prevent her from ever remembering, in order to protect her from herself and to protect other people. However, Junko had already planned ahead and had murders occur in the school. Despite not enjoying despair and killing, Yasuke was willing to do unethical things for the sake of protecting Junko, even if it caused him to feel horrible guilt.

Finally, Yasuke understands and admits to himself that Junko has only been using him. He is frustrated by her love for despair and he's angered when he assumes that she never cared about him. He states that he both loves and hates her, and eventually he decides to kill her when she is still Ryōko. However, he ends up getting killed by Junko in a fit of despair, as he is one of the few people she cares about the most. He was stabbed in the side by Junko and afterwards, she kicked his body until it was a bloody unrecognizable mess. He died believing that Junko did not care about him at all, but in truth this was not the case. Junko did not view him as a mere servant or even an ally and truly did love him as he did her as killing him resulted in her sadness and grief for his death and let him die in despair for the sake of increasing her own despair, proving this with the words “... you were the most important person to me of all...” after his death.

Fandom
This ship is mainly unknown due to Zero being the most unknown out of any Danganronpa Novel. It is confirmed to be canon.