Sekai Saikyou no Kishi wa, Kanarazu Shinu Heroine wo Sukuu Tame Isekai demo Saikyou no Kishi to Naru: Ryoute ni Hana wo, Ryoute ni Ken wo

He fell in love with the heroine and overturned her destiny to save her from her timely demise.

Abandoned by his parents, bullied in high school, and left in solitude—a young boy named Kenya Mikazuki. At the brink of despair, he encounters a fateful meeting in his only hobby, VR gaming. He has a fateful meeting with "Kaguya" and "Reina," the heroines from the immensely popular game "Knight of Giant." The time spent with the two heroines saved him, and he was head over heels for both of them. However, in the story, one of them is destined to die... To change that fate, he dedicated his life to mastering the game and becoming the strongest in the world. Suddenly, Kenya finds himself entering the world of "Knight of Giant"?! The strongest gamer embarks on a heroic tale of becoming the strongest in another world, in order to save the heroines he fell deeply in love with. The story begins.

(Source: Shogakukan, translated)