|Full Name||Saijou Leonhard|
|School||First High School|
|Year/Course|| First High |
Year 1 Class E Course 2 - 2095
Year 2 Class F Course 2 - 2096
Year 3 Class F Course 2 - 2097
|Ability Name|| Data Fortification |
Convergent Systematic Reinforcement
|Weapons & Equipments|
|Voiced By||Takuma Terashima (Anime)|
|Novel||Volume 1, Chapter 2|
|Manga||Volume 1, Chapter 3|
|Anime||Episode 1, Enrollment Chapter I|
Leo has great respect for Tatsuya, whose engineering skills and intelligence far exceed his own. Leo greatly trusts him and is willing to help him out however he can. However, that does not stop him from questioning Tatsuya's character at times and slightly fearing him.
Tatsuya seems to trust Leo as well. Aside from acknowledging his ability with "Fortification" magic, he uses Leo to test out a new weapon during the "Nine Schools Competition" arc and chooses him as one of his partners during the Monolith Code competition.
During the Yokohama incident, he learns that Tatsuya is part of the military, a secret unit called 101 Independent Magic-Equipped Battalion.
In volume 17, Leo acts in the same manner as before around the Shiba siblings despite now knowing that they are Yotsuba. When Mikihiko avoids the Shiba siblings entirely due to the knowledge that they are Yotsuba, he gets pulled back to his senses by Leo, as he states that yes, he is afraid of the Yotsuba name, but Tatsuya is his friend and has proven himself to be a good person in his own way.
The two hold a very friendly relationship. They often hang out together and have casual conversations, but also bicker quite a lot. They often quarrel over things, ideas and motives etc. This often gets referred to as a "lovers-quarrel". They deny it every time.
This relationship later evolves momentarily into a "master-student" one, when Erika chose to teach Leo some of the Chiba family's secrets in order to improve his fighting ability.
It is shown that the other characters in the anime have considered the possibility of them being a couple.