Shounen ga Otona es un del estudio Kyoto Animation. No hay material fuente, por lo que nadie puede darte spoilers del final.

Keep in mind that I can also try to help you find the Spanish subtitles or provide a general summary of a series if you provide more information!

After checking major anime databases (MyAnimeList, AniList, Anime-Planet) and fan translation sites, no official or fan-translated series matches "Shounen ga Onota" exactly.