Souya Minamino

Souya Minamino is one of Hayate and Ayumu's friends who attends Hayate's previous high school, Shiomi. According to Ayumu, he's really (and only) good at swimming. He is also the protagonist of Kenjiro Hata's previous work, Heroes of the Sea Lifesavers.

(Source: Hayate no Gotoku! Wikia)