An anime where the male lead travels through another world (I want the whole one)

Answer 1

There were many animes in which the male lead traveled through the different worlds that could be referred to as the following famous ones:
1. Death Note: Written by Thrush Ohba, it tells the story of the protagonist, Yagami Tsuki, who uses a notebook that can kill people to realize his dream, but at the same time, it also triggers a series of events.
2 " The Gate of the Stone of Destiny " was created by Okada Touji. It tells the story of a group of physicists who discovered an unexpected truth in their research on time travel. Their discovery triggered a series of bizarre events.
[3]" The Attacking Giant ": Written by Keiyama, it tells the story of the war between humans and giants. The protagonist, Allen, grows up in the war and develops complicated relationships with other characters.
4." Tokyo Ghouls ": Written by Mamoru Hosoda, it tells the story of a group of controlled puppets surviving and fighting in human society. The protagonist, Kimki Ken, is forced to become a ghoul and embark on a new adventure.
5. Catalog of Forbidden Magical Books: Written by Dangma Shangjou, it tells the story of the protagonist who accidentally discovered a mysterious forbidden book in the library and was involved in a series of dangerous events.