Let This Grieving Soul Retire, Vol. 1 (manga)

"There’s only one thing I’m aiming for-to be the world's
strongest hero."
Cri makes an oath with his friends to become the strongest
hero in the world...but his
hopes are quickly dashed when he realizes that
his talents lie elsewhere. Despite the
reality check, the expectations from
the people around him seem to rising
exponentially every day! Now Cri must
deal with this huge misunderstanding as well as
the outrageous
consequences!