Infinite Titles

Level 1 Hunter Koutake Takeru gains a mere hundred-thousandth of the experience points he would get from even the weakest goblin.
Undeterred by this hopeless reality, he spent ten years single-mindedly hunting goblins. Just as he’s about to level up, he unexpectedly encountered a boss monster.
After a fierce battle, he maxed out his experience points. However, for some reason, he still didn't level up. Then, in a desperate fight for his life, he earned the title "Weakest Hero," that has an extraordinary effect: "All titles you own are always active."
After defeating the boss, Takeru realized he could fight using the power of titles even without leveling up. He then resolves to collect all kinds of titles and rise to the top while staying at Level 1!