SaikaHachi

SaikaHachi is the slash ship between Saika Totsuka and Hachiman Hikigaya from the OreGairu fandom.

Canon
Saika was in the same class as Hachiman for two years and they attend the same gym session/class at school. Saika is very kind towards Hachiman. Saika usually calls Hachiman by his first name despite not knowing him for very long. Implying that Saika really wants to be his friend. Hachiman sometimes responds kindly even though it makes him uncomfortable sometimes, but Saika enjoys it nonetheless.

Hachiman was completely unaware of Saika's existence, despite being in the same class for two years. Hachiman says this is because he never pays attention to girls. In their second year of high school, Saika is introduced to Hachiman who finally learns that he is actually a boy.

Hachiman often has 'romantic thoughts' about Saika, and quickly stops himself after reminding himself that Saika is a male. Although sometimes he stops to think if that's really an issue or not but eventually snaps out of it. Saika is one of the few people who truly wants to be close friends with Hachiman, despite Hachiman pushing people away. Saika also mumbles Hachiman’s name in his sleep, which makes Hachiman blush while irritated.

Saika is one of the few to know the real reason of the roof incident during the Cultural Festival, though he believes Hachiman has his reasons for acting the way he does and still proceeds to hang out with him. After the athletic festival, when their entire class shows their dislike for Hachiman, Saika still socializes with him and tries to get even closer to him. He admires Hachiman for who he is deep down. And in return, Hachiman allows him and the two become extremely close friends

Saika says that he thinks Hachiman is a cool person further confirming his admiration for him. Saika also participated in a meeting to contributing in helping Hachiman to stop Yui & Yukino from participation as a candidate for student council. Saika also showed interest and willingly teamed up with Hachiman a few times despite no one else wanting to participate with him. In the light novel, it is also shown that he is able to tell when Hachiman is depressed or restless in many cases. They often seem to hang out together in places where couples would normally go, like restaurants and movies.

Fanon
The ship sailed as a result of the small ship tease between the two and the fact that Saika is one of the few people who actually managed to get close to Hachiman.

The fact that Hachiman thinks of Saika romantically sometimes and gets flustered whenever Saika does something that could be qualified as cute also helped the ship sail.

It is naturally rivaled by Hachiman's canon ship with Yuki although some would argue that they both got a fair amount of ship tease and Saika x Hachiman would've been Canon had Saika actually been a girl. But regardless HachiYuki shippers still understand and respect SaikaHachi shippers for the most part.

Fandom
FANFICTION

Trivia

 * Saika is one of the few to have Hachiman's cell number and e-mail address, along with Hayama, Yui, Shizuka, Taishi and Haruno.
 * Saika always calls Hachiman by his first name
 * Apparently Yoshiteru Zaimokuza ships them as he claims that whenever Hachiman looks at Saika he 'Falls in love'
 * Hachiman states that he wants to protect Saika's smile at all costs
 * They may have bathed together as Hachiman often thought of it while they were on their field trip and as he was walking he thought "Well guess I should take a bath with Totsuka then"
 * Hachiman once stated that he has no friends that are boys but then Saika reminded him that he's a boy and Hachiman just blushed saying that he forgot about him for a moment
 * Hachiman said that if Saika weren't a boy he would've confessed to him a long time ago