By manager, do you mean in showbiz or corpo?
Idol x manager
https://www.mangago.zone/read-manga/lie_cry_like/ not manager, more like caretaker
https://www.mangago.zone/read-manga/koi_ni_wa_mukanai_shokugyou/
https://www.mangago.zone/read-manga/kimagure_to_amagami/
https://www.mangago.zone/read-manga/in_my_closet/
https://www.mangago.zone/read-manga/one_week_family/
https://www.mangago.zone/read-manga/do_shenshwcho_wo_ikenai_goshido/ editor- novelist
https://www.mangago.zone/read-manga/run_away_assistant_manager_ha/
https://www.mangago.zone/read-manga/i_don_t_cry/
Both
Thankiees <3
Any manager BL??