Undefeated by the Rain

Undefeated by the Rain (雨ニモマケズ,) is the ability of Kenji Miyazawa.

Description
Undefeated by the Rain grants Kenji superhuman strength. This allows him to lift and overturn cars (including an entire tank) with relative ease and pull street signs out of cement. He can also dismantle a rail pole from a train track with his bare hands and rip from the wall a steel door that is similarly used in high-security bank safes.

The ability also appears to grant him superhuman durability, as he can withstand a direct blow to the head with no apparent damage and a barrage of bullets without getting severely harmed. Kenji also once mentioned getting kicked in the head by cows all the time in his village and seems to have survived with little to no damage.

However, as a condition, Kenji can only activate his ability on an empty stomach. Otherwise, he ends up sleeping after eating. Despite his overwhelming strength, some people have proven to get on par or even block Kenji's super strength, including Chūya Nakahara with the help of his gravity manipulation and Saigiku Jōno through his surgically-enhanced strength. Though Kenji is seemingly impenetrable against bullets to a fault, he is nonetheless vulnerable against swords, as shown when he suffered two casualties after getting impaled by Tetchō Suehiro's extended saber and by Michizō Tachihara's manipulated katana.

Moves

 * Ground Pound: Kenji can smash the ground with a strong force, resulting to it being crushed into pieces.

Derivation
The ability is a reference to Be Not Defeated by the Rain (雨ニモマケズ,), a poem by Kenji Miyazawa. It was found in a small black notebook and shows the virtues of enduring harsh conditions with good grace.

Trivia

 * In the anime, Kenji receives Akiko Yosano's treatment following their first encounter with the Guild. However, the manga shows Kenji sleeping after the incident and implies that he did not receive (let alone need) Yosano's treatment, most likely surviving the Guild's attack through his superhuman durability.