Hoshina has short black hair with a fringe. His eyes have especially long lashes.
Hoshina is a very stoic, quiet person who is nonetheless easy to get along with. Good-natured and polite with a side of old-fashioned gentlemanliness, he is helpful, honest and a very fair player, relying only on his own and his team's strength and hard work and never looking down on others despite coming from a highly talented family and a powerhouse team. He does, however, take soccer very seriously, sometimes to the point of being a worry-wart and mood-killer for his teammates, and dislikes cheering while the match is ongoing, especially if that cheering is directed at him. Generally he is very straightforward and has trouble dealing with people who take things less seriously than he does.
Hayato Kaidou and Shizuka Ura: Hoshina has known Kaidou and Ura since they were middle schoolers. In all the years of playing together they have developed a strong bond despite their different personalities, calling each other by nicknames and being seen hanging out together off the soccer pitch as well as on it. He and Kaidou especially share a special bond with being, respectively, the team's playmaker and pinch scorer, and a failure to pass to Kaidou in a crucial moment during a past match haunts Hoshina to this day.
Mitsuru and Seiya Hoshina: Hoshina's two older brothers are great soccer players as well, as they are respectively in the J-league and the top college scorer. They came to watch Takumi's match against Seiseki. 
Chikako Ubukata: Hoshina first meets Ubukata when the latter comes to scout out Touin in disguise and instantly offers to guide her to the pitch and have her interview him. All along he treats her in a gentlemanly manner, and when his teammates reveal that she is, in fact, Seiseki's manager coming to spy, he doesn't bat an eye but simply tells her to keep watching because Touin has no secrets. When Seiseki later wins the match thanks to her research and strategy, he acknowledges her accomplishments with a slight bow and, although they don't see each other again for some time, seems to continue to hold her in high regards. In fact, it is heavily hinted that he starts to develop a crush on her; he once pays her room a visit during nationals, and later on he is found looking for her when watching Seiseki's match against Ryouzan. Whether or not Ubukata reciprocates has yet to be clarified, although she appears to have at least some interest in him.
- His special skill is soccer.
- His favorite thing is the cosmos but he doesn't have anything he dislikes in particular.
- His favorite saying is "Live as if you were to die tomorrow, learn as if you were to live forever" (Gandhi)