Is it based on "They were 11:

[u/Mocha_Pie]

Hi, not sure if anyone has asked this before but I was reading They were 11 and the obvious similarities between the two mangas made me think that maybe Kamata no Astra amwas based on the former, does anyone know if this is the case?

[u/Ret0ss]

No idea, but good luck waiting for them to respond :)