MTL - Naruto: Ten-year-old Kaleidoscope, Opening Betrayal Konoha - Chapter 22

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates

A young man finally managed to become an immortal, a powerful cultivator able to lord over millions of souls. He took advantage of his tremendous luck and fortune to become the youngest immortal in history. He now wants to create his own sect and enjoy life, one filled with female disciples!

Chika Satomi is a beloved and beautiful girl in the class known as the ‘Angel of Peace.’Ichinose Sōma, who is a fanatic about making sweets, asks Chika to be a taster for him after school when he makes some sweets.Saying things like,「I also want to try various things――」「…Ichinose-san’s embarrassed expression is really cute…」Sōma ends up watching over Chika, who keeps teasing him.Though usually passive, for some reason, Chika teases Sōma with a sly smile, showing her mischievous side only to him, and as a result, Sōma’s after-school hours become filled with sweetness!?A sweet and thrilling romantic comedy with a naughty angel woven together by confections!

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).