It's Not Easy to Be a Man After Travelling to the Future (WN) - Chapter 1497: I See

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!?

I became the childhood friend of the protagonist in a novel. The childhood friend who died from taking drugs.

Author Note: This story is only for those who like reading about overpowered protagonists, as our MC is going to be more than just overpowered.He is going to thrash anyone who comes in his way while enjoying his life.Also, it's a world travel novel; for those who have an interest in world travelling.................................................................The story is about a person who has lived through many lives, seen incredible things, and become one of the strongest if not the strongest beings around. Although he struggles to remember his past, he is determined to grow even stronger by utilizing his personal system as that would bring back his memories. He has one main mission - to enjoy life to the fullest - and he is absolutely committed to achieving it.Follow through the journey as he becomes the strongest (again?) and regains his memory while also enjoying his life along with his system and some other people.

The head of the London Association of Mages, the most powerful Saint Archmage in the world, Audrey Davis, accidentally transmigrated to another world due to a magic accident. She was an 18-year-old human girl.