Naruto: The Outsider's Resolve - Chapter 1.8 (018):

The frail and sickly Wen Jiexi had always wanted one thing: a healthy body and like a dream come true, one day, she was selected by the system!

System: The amazing me shall grant you a strong physique and divine strength! However, you have to maintain your health through monthly missions! If you fail to complete them~well, then you’ll stay as a female King Kong, forever~

Wen Jiexi: What?! Will I no longer be able to live my life freely again?!!

Mother with an alarmed expression: My frail daughter is actually trying to do the most sit-ups possible?!

Father made a strange face: My delicate daughter ran on the treadmill for an hour?!

Brother’s expression crumbled: Can anyone tell him how his cute little sister who is as precious as a delicate white flower…was actually able to use one punch to break a sandbag and smash a hole through the wall!!!

Through a series of unexpected circumstances, she was pulled into the entertainment industry and became a female martial artist!

Female Fan: Our darling Wen is the most awesome! She’s even more handsome than a man!

Male Fan: The girls today are so domineering! To be able to throw away all of one’s shame, I want that feeling too!

The frozen expression after being hugged by the princess from behind: …..

Wen Jiexi held up a hand: No, no, no! It’s not like that!

- Description from Novelupdates

Alexander Sirius’ life has hit rock bottom, his parents hate him, he lives under the shadow of his genius sister, and even his own girlfriend cheats on him, all this changed when he gets another chance.

Transported to Another World? Cultivation World? A Modern World? How about all of them? From countless planets in the Universe, Each planet has its own technology, culture, and civilization.

In another world, carrying all the traumas with him, would he manage to reform himself and become the sovereign of his life?

[Host has Gacha System]
"Okay, what can you do?"
[I am a Gacha System, so I only have Gacha]
"Only Gacha? How about godly pills or overpower techniques?"
[Everything can be acquired with Gacha because Gacha is all you need]
"Gacha usually is only a complement for the Main System such as RPG System. You are not useless, right?"
[THERE IS NO USELESS SYSTEM, ONLY USELESS HOST]

Join this 'Loser" with his 'Useless System' As they start their journey.

Another Work: The Magician of Sound

(I'm not a native English speaker. I have done some editing to fix my Early Chapters' Mistakes, but it is still not all of them)

******EXTREME CAUTION******

If you are searching for MC with a strong mentality and high intelligence or Independent and Strong Heroines from the start, this is not your thing. This is going to be a 'very slow' pace development in MC Character, the same applies to the Heroines. So rather than Giving bad reviews, I advise you to 'Not' read it rather than complaining about it later Discord: https://discord.gg/HYvMbb4

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!

Transcend to become the prince of Daxia, activate the Devil Emperor Summoning System, summon the powerhouses from other worlds, and fight for hegemony in the heavens!

If I were the Devil Emperor in the future, I would definitely let your blood stain the sky!

- Description from novelbuddy