
Quick answer — sajou no hana performed 4 anime themes, including "DanMachi S4 - Ending 2 | Kirikizu" from Is It Wrong to Try to Pick Up Girls in a Dungeon? IV, "Evergreen" from Is It Wrong to Try to Pick Up Girls in a Dungeon? III, "Hoshie" from Sirius the Jaeger.
sajou no hana performed the anime theme songs "DanMachi S4 - Ending 2 | Kirikizu" (Is It Wrong to Try to Pick Up Girls in a Dungeon? IV), "Evergreen" (Is It Wrong to Try to Pick Up Girls in a Dungeon? III), "Hoshie" (Sirius the Jaeger), "Hydrate" (Is It Wrong To Try To Pick Up Girls in a Dungeon? V).
sajou no hana's first listed anime theme is "DanMachi S4 - Ending 2 | Kirikizu", the ending of Is It Wrong to Try to Pick Up Girls in a Dungeon? IV.