Toaru Majutsu no Index SS - Volume 1, Chapter 4: A Drunk Mother’s Circumstances. The_Two_Leading_Roles.

Karl, a young man stuck in a rough patch after losing his job and burning through almost all his savings, wandered through the cold, dark streets of Eldoria. On the damp, silent sidewalks, he stumbled upon something bizarre: an old gacha machine mysteriously appearing at every corner he turned, almost as if it was following him. Driven by a mix of curiosity and the overwhelming weirdness of the situation, Karl finally gave in and used his last bit of money on the machine. From the gacha ball, he pulled out a card with a barcode.Back in his cramped apartment, curiosity finally won over caution, and Karl scanned the barcode. To his shock, an app called “Common Sense Manipulation App” installed itself on his phone, claiming it could alter people's “common sense.”------Support Me By Gifts or Power Stones-----

An Hao leaped, thinking she had died, but to her surprise, when she opened her eyes, she found herself back in the year 1985. To live a second life, did she have to endure the abuse of her stepmother and stepsister again, the dislike of her mother-in-law and disdain from her sister-in-law, and the betrayal of her best friend who bravely became the other woman just to slap her in the face and climb the social ladder? Was she supposed to end her miserable life in poverty again? An Hao's answer was, “Eat! Shit! No!” She was determined to make something of herself, to get rich by capitalizing on her knowledge and aim for a well-off life. This time around, she was going to be the protective big sister who reformed her worthless little brother who had died a wretched death, and the virtuous wife to make up for her past neglect of her husband! She wouldn't let this life go to waste in despair! A malicious best friend? Coveting her man? Not a chance! Go hang out wherever it's cool! Cough cough, how did she not realize in her past life that this “Stoic King of Hell” was so indecent. Decent? You've had your fill of decency during the day.

“Do you like me?” “Yes...” “When did it start?” “A long time ago...” “Will you always like me?” “The fireworks...will always be with you...”Looking at her upturned face, the girl's timid hand was gently lifted up. The warmth in her palm has always been so familiar. “Want to go watch the fireworks together?” “Yes.”The summer fireworks blooming in the deep night are just like your touching and tender smile twelve years ago.----------------------------------PS: Youth daily life story, childhood friend single female protagonist.

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?