Tokoshie (永久 -トコシエ-)

"Tokoshie" (永久 -トコシエ-) is a 2024 song by MY FIRST STORY and HYDE, released under the collaboration name MY FIRST STORY × HYDE. It was used as the ending theme for Demon Slayer: Kimetsu no Yaiba's Hashira Training Arc (鬼滅の刃「柱稽古編」), the ufotable television anime series.

The song was released as a digital single on May 20, 2024. Apple Music classifies the release as rock, and the music, lyrics, and arrangement are credited to 梶浦由記.