Sekai Saikyou no Doryokuka ~Sainou ga (Doryoku) Datta no de Kouritsu Yoku Kikakugai no Doryoku o Shitemiru~

In order to defend someone precious to him, he’ll use “Effort” to become invincible?! In this world, at twelve years old, all children have their “Aptitude” or special skill revealed which will guide them in the future. With cool Aptitudes such as “Knight” or “Wizard” being not uncommon, Rivelle is given the less-than-becoming Aptitude of.. “Effort”, which no one has ever heard of. His childhood friend, Anna, however, gains the Aptitude of Dragon Knight and with a vow to protect her, Rivelle strives to become the strongest in the world!