Your query is likely a of Japanese lyrics + request for Spanish subtitles + working source. Without the exact original song title, the best next step is to identify the real Japanese title by listening to the audio or sharing a clip in lyric identification forums.
Shinseki no ko to tomatta kara... = “Because I stayed with my relative’s child…” Your query is likely a of Japanese lyrics
Searching the specific phrase, often accompanied by #animeclip, reveals viral moments on Facebook and TikTok. = “Because I stayed with my relative’s child…”
Genre: Drama / Fantasy Runtime: 1 h 38 min (Japanese) – 1 h 44 min (subtitle version) Release: 2023 (Japan) – streaming on Work (sub‑titled English version) often accompanied by #animeclip
It looks like you're trying to find a video or subtitle file for a phrase that mixes Japanese and Spanish.