Sakura Alien 2

In this visual novel Takagi Haru is a normal university student with an abundance of love for the stars. As a member of his university's astronomy club, alongside the sweet but somewhat ditzy Hiyori, Haru means to devote his life to the stars. He doesn’t have any time to mess around with cute girls…

At least, that's what he always thought – until an alien princess from another planet, Ena, lands on his lap, and declares herself to be his future wife.

Haru ends up taking Ena in, as she has nowhere else to go, and Ena and Hiyori soon hit it off. Now, the three of them are good friends (or perhaps something more) – but malevolent forces are seeking to undermine their relationship.