The Fruit of Evolution: Before I Knew It, My Life Had It Made

Hiiragi Seichi is an unattractive high schooler who gets bullied; one day, a mysterious voice suddenly rings out over the school's PA system and sends them all to another world.

After Seiichi defeats a gorilla-like monster, a Kaiser Kong, she proposes to him.

Seiichi leaves the forest with Saria and heads to the royal capital so he can find out where his friend from school went.

Seiichi and Saria train under Artoria to become adventurers; they are teleported into a dungeon by a demon's trap.

Seiichi rescues Artoria with her on the verge of death; he faces the Black Dragon God.

Seiichi's attempts to cheer up Artoria; Seiichi and Saria pass their tests and successfully join the adventurer's guild.