BoKuro

BoKuro is the slash ship between Bokuto Koutarou and Kuroo Tetsurou from the Haikyu!! fandom.

Canon
Bokuto is the ace/wing spiker at Fukurodani while Kuroo is a middle blocker at Nekoma. Both characters are 3rd years and also the captains for their teams. Throughout the series, these two have a strong friendship; often teasing one another. But when they face each other during matches, they become competitive with each other.

We first see the two during the Tokyo training camp, in Gym 3, when both of them try to get Tsukishima to practise with them. During the practise, when Kuroo blocks Bokuto's spike, Kuroo cheers while Bokuto gets annoyed. The next day, after Kuroo teaches Tsukishima, Kuroo tells him he should be able to "shut this owl up" while Bokuto pulls faces at him, showing their banter side.

Fanon
According to AO3, BoKuro is the 9th most popular in Haikyu!!

Fandom
Fan Fiction
 * Bokuto/Kuroo tag on A03