Tsuihousareta Bannou Mahou Kenshi wa, Oujo Denka no Shishou to Naru @Comic

"I... want to be like you!" Solon, a magic swordsman who was banished from the Knights (party), is told this by Philia, a lonely princess who is semi-imprisoned. At the request of his mentor, Solon becomes the girl's tutor and begins to impart magic and knowledge to her, who has lived her life admiring him—but on the very first day, a plot to assassinate Philia erupts!? In order to protect the innocent girl, he ends up living and sleeping with her. On top of that, his childhood friend, the Knight Commander, shows up at the palace, and he is pursued by a cunning personal maid, and so his days become more lively in many ways...? A swordsman who was banished because of his omnipotence and a princess who harbors a secret about her birth. The encounter between these two will change the fate of the country in this palace adventure fantasy that is more than master and student, but less than lovers! (Source: Comic Corona, translated) *Note: Chapter count includes seven bonus chapters.*