Seina Yamada has been waiting so long to return to his home, Earth.
But so much has changed; his sister is engaged to Kiriko's brother Kai,
and his parents' old store is now a huge mall.
Furthermore, he is to stay at Kiriko's mother's house...
the non-compulsory high school 
would have been hard here.
لكانت حياة المدرسة الثانويّة غير الإلزاميّة صعبة هنا
je pense que j’aurais eu du mal
à aller au lycée.
il liceo non obbligatorio 
sarebbe stato più complicato qui.
a educação obrigatória
teria sido difícil aqui.
я бы не смог ходить в местную
необязательную старшую школу.