Tensei Shoujo wa Mazu Ippo kara Hajimetai: Mamono ga Iru Toka Kiitenai!

Even as a working adult, Sarasa Ichinokura suffers from an unshakable fatigue that’s plagued her since childhood. She goes to bed one night, exhausted from her office job, and encounters a goddess(?) who informs her that her perpetual lack of energy is actually due to a deficit of “mana.” Then, with