【PC+安卓直装】Muv-Luv

平凡的學園生白銀武（しろがね　たける）面前突然出現的少女，冥夜。

她硬是闖進他家，甚至就此住了下來。這起事件將使主角與青梅竹馬純夏、同班同學壬姫、千鶴、慧，以及摯友尊人之間的關係產生變化……

平凡な学園生、白銀武(しろがね　たける)の前に突然現れた少女、冥夜。

彼女は家に押し掛け、住み着いてしまう。この事件が主人公と、幼馴染の純夏、クラスメイトの壬姫、千鶴、慧、そして親友の尊人との関係に変化をもたらすことに…。

This game consists of two parts: Muv-Luv Extra and Muv-Luv Unlimited. Unlimited is unlocked after you get the endings of the two main heroines (Sumika and Meiya) in Extra.

Muv-Luv Extra:

Shirogane Takeru is a typical high school student with a lazy attitude and a love for the virtual reality mecha battle game Valgern-on. Even though he didn't really want it, he is popular in school mainly due to his daily fights with his osananajimi (Sumika) attracting too much attention. His life takes an unexpected turn when he finds a girl (Meiya) he doesn't remember ever meeting in his bed one morning. That girl is later revealed to be the heiress of one of the biggest zaibatsu. She immediately moves to his house and starts changing his life for the good with her one-track-mind and unlimited resources...

Muv-Luv Extra, the main part of Muv-Luv, takes place in the same world (and general area) as Kimi ga Nozomu Eien and Kimi ga Ita Kisetsu. The Sky Temple family restaurant is mentioned and visited, and Suzumiya Akane makes an appearance.

Muv-Luv Unlimited:

One day Takeru wakes up late, wondering why Sumika or Meiya didn't wake him up this morning. Not seeing any signs of them he gets a bit worried and goes out of his house only to see the town he lived in all his life in ruins. After getting past the initial shock he decides that this must be a dream and decides to enjoy it as much as he can...

[Partially from Wikipedia]