Age 17, Height 145cm, Weight 39kg, Birthday January 2nd. Hobbies include napping and idling. She is a 3rd-year student at Abydos High School. She usually has a laid-back attitude, finding most things bothersome and living life as it comes. However, as the eldest, she plays a role in mediating her juniors who propose illegal, unrealistic, or dangerous solutions to clear the school's massive debt. It's also characteristic that she intentionally hides this thoughtful and diligent side from her juniors. As shown in her Bond Story, she has a particular fondness for marine life, especially whales. The PV cut above shows a mobile with whales and fish hanging by Hoshino's bedside. In the third PV, she's seen floating on the water at the beach, hugging a whale-shaped float. Uniquely, she refers to herself as an 'ojisan' (old man). Considering Hoshino has been through a lot since her first year of high school, it's not strange for her to call herself an 'ojisan'. It seems she adopted this nickname because she believes she's already too jaded and lacks feminine charm compared to other students. Combined with her optimistic speech and her catchphrase 'Uhe~', it's quite a fitting nickname.