Alpha's Bite Between My Legs - Chapter 1: The Letter

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

Side story of Kyoukai Senjou no Horizon bundled with the first press release of the 1st, 3rd, 5th and 7th Blu-ray volumes of both seasons of anime.

This side story follows Asama, Kimi and Mitotsudaira aboard Musashi one year before the beginning of the main story, as Asama is considering to create a music band together with her two friends for the next festival in Aki, a territory under the governance of K.P.A. Italia.

I just lost myself in the deep and shallow temptation of her.
——by Jiang Hanyu
Everyone knows that the person Nan Gao doesn’t mess with is Jiang Hanyu
She is arrogant and fierce, relying on beauty, a proper little overlord in school
Everyone thinks that the best relationship with Jiang Hanyu is to call him brothers.
But one day, someone found that Jiang Hanyu was holding the hand of the goddess of coldness in the class and lowered his eyebrows after class.
Unruly girls become gentle and charming
He also said in an unbearable and irresistible voice, “Si Nian, will you give me a kiss?”
Then everyone knew that the best relationship with Jiang Hanyu was…

TIPS:
1. The Great Demon King X Miss Gao Leng
2. Campus text

- Description from novelbuddy

As a child with an unattainable dream, I yearned to become a Hero, but I veered off the right path. Looking back, my aspiration to save others was nothing more than a foolish dream. I now realize the magnitude of my sins and the impossibility of atoning for them.