Baka ni Kokuhaku

Ayumu Ootsuki is a space lover with an ambitious dream—to meet an alien. Despite lacking friends or romantic experience, she started the Astronomy Association by herself, which is the only place where she feels she belongs. One day after school, she dropped an association poster, but an upperclassman picked it up for her. The upperclassman introduced herself as Hayami, and Ayumu completely fell in love at first sight when Hayami recognized her passion! Ayumu's mind is now filled with love, and she goes all out to share her feelings. However, the senpai seems to already adore something else. She fell for a fitness junkie?! A peculiar girl's straightforward romcom!!

(Source: Kadokawa, translated)