TsukkiYama

TsukkiYama is the slash ship between Tsukishima Kei and Yamaguchi Tadashi from the Haikyu!! fandom.

Canon
Tsukishima and Yamaguchi are both first years and members of the Karasuno High School volleyball team. The two first met when they were younger, Tsukishima standing up to those who were bullying Yamaguchi. They later met when joining a volleyball team during junior high, and their friendship developed from there. The two have a very close bond, and are in the same class. It is noted that Yamaguchi is also close with Tsukishima's older brother, Akiteru, by his first name.

Though Yamaguchi usually just follows Tsukishima and Tsukishima seems annoyed with him, Yamaguchi sometimes snaps at him when he is not taking things seriously. For example, in the Tokyo Expedition Arc, Yamaguchi and him have a short argument, which ends in Tsukishima asking when Yamaguchi "became so cool."

Fanon
Tsukishima and Yamaguchi have been dating since junior high.

Trivia

 * When Yamaguchi's voice actor was asked what type of person Yamaguchi is, they replied with "they love Tsukki very much".
 * The two met when they were younger, after Tsukishima stood up for Yamaguchi when he was being bullied. However, when they met later at a junior volleyball club, the latter thanks Tsukishima for rescuing him, however Tsukishima did not remember this incident.