We Without Wings: Under the Innocent Sky [TV]

Also Oretachi ni Tsubasa wa Nai

Haneda Takashi has a secret he cannot speak of. To leave his dull school-life, he was supposed to have escaped to another world. However, he is reeled in by certain ties on his heart. One of these is Kobato, his awkward younger sister. The other is Watarai Asuka, his negligent girlfriend.