Kunigiri

Kunigiri is the slash ship between Rensuke Kunigami and Hyoma Chigiri from the Blue Lock fandom.

Canon
Rensuke and Hyoma are both placed together on Team Z during the first selection. Although the manga does not show them interacting much during this point, they are rather touchy with each other towards the end of the first selection and Rensuke also gently teases Hyoma for wanting others to stop eating their celebration food when he himself is eating it as well. The official fan book however, revealed that Hyoma would join Rensuke when he was working out and chat while doing his leg exercises, and Rensuke would attempt to assist Hyoma when trying to dry and style his hair, even when the other members of their team were growing impatient. The 'Additional Time' segments of the anime showed the latter, with Rensuke offering a headband to Hyoma to help him style his hair, telling him he understood his problems since he has two sisters. Rensuke also referred to Hyoma as 'ojou-sama' during this segment, a term for a noble lady in Japanese, denoting Hyoma should be respected and treated with care even when the others are tired of him taking long with his hair.

Another 'Additional Time' segment showed Isagi and Igaguri attempting to trade their food for Rensuke's, since his higher ranking on their team earned him better quality food. However, Hyoma also requested to trade upon seeing this, with Rensuke immediately agree and offerings food, with shoujo bubbles appearing around them and Rensuke using a phrase that is also used to denote accepting confessions in Japanese.

In the second selection, upon seeing each other have passed, Rensuke and Hyoma immediately decide to team up with each other. They end up creating a trio of them and Reo Mikage. When their group is shown, Rensuke and Hyoma again appear very close with each other, even sitting rather close when taking a bath alongside Reo and Isagi's team. Before they play against Isagi's team, Rensuke asks if it's normal to feel so excited, with Hyoma responding that his excitement comes from the two of them being teamed up together. During the game, they continue to show a closeness to each other that is not present with Reo.

After being defeated by Isagi's team, Hyoma is picked to move on as per the rules of the second selection. Hyoma is shown to be very distraught about leaving Rensuke, but promises him that he'll be waiting for Rensuke to come win him back so they can play together again and defeat Isagi. This sentiment encourages Rensuke, who keeps his pride while also having to deal with the emotionally distraught Reo. When Hyoma makes it past the second selection, he waits to see Rensuke again, and is incredibly upset when he finds that he did not also pass, getting upset when Shidou disses Rensuke's soccer skills.

When Rensuke returns after the wild card program, he and Hyoma meet once again. He is rather pessimistic and seemingly tormented from his time in the wild card program, telling Hyoma he is not the same person Hyoma knew and calling him a 'naive princess'. Hyoma on the other hand is determined to bring the Rensuke he'd known back, telling him he will still play as if Rensuke has never changed and is determined to 'awaken' the hero inside of Rensuke once more.

Fanon
Kunigiri is the most popular ship for both Rensuke and Hyoma in the fandom, though rivaled occasionally by Chinagi, Isagiri, and Kunisagi. The close relationship the two had throughout the second selection arc, especially given how the two reference their respective nicknames of 'Princess' and 'Hero' and how the two fit together, made the ship gain attention in the manga, though the lack of Rensuke content due to him being eliminated from Blue Lock for a period has allowed other ships to take over general popularity in the fandom, such as Reonagi and Bachisagi. With the release of the anime and its added extra shorts involving Rensuke and Hyoma being very close, the ship once again garnered popularity, as well as the official fanbook confirming Rensuke to be bisexual.

Fandom
Chigiri Hyoma/Kunigami Rensuke on Ao3

Trivia

 * In the official fan book, Rensuke's type is described to be 'someone gentle and cute'