Saimaki

Saimaki is the het ship between Shuichi Saihara and Maki Harukawa in the Danganronpa fandom.

Canon
Shuichi and Maki got along well after the events of Chapter 2, after Kaito Momota brought Maki to their training regime. This resulted in the three doing exercises together, although Maki outmatched the two boys at everything they did. Shuichi seemed impressed with Maki's skills, and the three began to meet up nightly to do these exercises. As the two grew closer, Maki began to feel more comfortable around Shuichi, although she still had some trouble trusting others. Despite her cold and rather intimidating demeanor, Shuichi is one of the students who trusts Maki despite her status as an assassin.

Although Shuichi initially only trusted Maki because of Kaito, he grows to genuinely care for and believe in her. In Chapter 3, when Maki confides in him about her not feeling "human", Shuichi assured her that he can relate, as he has his own insecurities about his work as a detective. Because of this, Shuichi strongly supported Kaito's decision to take down Maki's "mask", as he believed he is the only one who can help her open up.

During the events of the virtual world in Chapter 4, Maki did make a point to remind Shuichi that he's a person before he's a detective, which he's touched by, despite her telling him he's more reliable during a murder case than daily life. Nonetheless, it's apparent the two have grown quite close to each other, with her asking if he's okay, making sure if he and Kaito aren't fighting when Shuichi forcibly logged him out to test something.

In Chapter 5, their relationship is slightly strained after Kokichi captured Kaito. When Maki attempted to save him, Shuichi held her back out of fear for her safety, claiming he did't care if she is upset with his decision, or even wanted to kill him. Although Maki backs down, she angrily calls him a coward, to Shuichi's dismay. During the fifth trial, she repeatedly attempts to steer the crime into her own fault, threatening and insulting Shuichi when said Kaito was the one who survived, claiming that he was getting in her way to defeat Kokichi Ouma. Shuichi was visibly saddened by the fact that Maki did not share his belief in Kaito's survival, as he thought she would be take his side on the matter. Despite this, he still strongly wanted to believe in Maki when it started to appear as if she was the culprit, and appeared relieved when Maki's testimony turned out to be flawed, proving she was not Kaito's killer. However, the two came to a disagreement again after Shuichi suggested Kaito murdered Kokichi, until Kaito came out and confirmed Shuichi's story.

During Chapter 6, Shuichi and Maki rely on one another as they investigate the school together. Shuichi expressed happiness at the fact that he and Maki have reached the point where he can tell that she's joking. During the last trial, it was partially because of Maki and K1-B0's offer to sacrifice herself that inspired Shuichi to abandon his vote, as he admitted the thought of Maki dying scared him due to what happened to Kaede and Kaito. Shuichi gave Maki courage to end the Killing Game, which resulted in her abandoning her vote as well. The two, along with Himiko, later survived together, escaping to the outside world.

After Kaito's execution in Chapter 5, Maki and Shuichi went to their normal training spot and had a short, but emotional conversation about the events that had transpired, seemingly putting their previous falling out behind them and mending their friendship. Joined by Tsumugi Shirogane and Himiko Yumeno, they trained together and mourned Kaito. Shuichi and Maki then resolve to put an end to the Killing Game together along with everyone else

Fanon
The ship sailed as a result to their friendship growing throughout the game and their closeness to Kaito. With Maki having confirmed feelings for him and Shuichi being his best friend. Along with the fact that they are 2 out of the 3 survivors. Both losing their respective love interests during the killing game also helped.