Tetsuo Takahashi, or as the girls simplify to just Takahashi-sensei, is what I deem to be the perfect example of a real life teacher solving "real life problems" (ya monsters but still) and doing an amazing job at it. Koro-sensei from Assassination Classroom is the only other teacher that comes close. Now, I'm a teacher myself so I think I got a lot more out of this anime than many others would and that is because I saw Takahashi-sensei in a very unique perspective almost at a personal level. Anime usually has a lot of disconnect between its fans and those who watch it because we aren't all Gundam pilots, we don't all use crazy magic, we aren't all soul reapers, but some of us do teach or have other careers presented in the series we watch. So with what we do lining up, knowing what it's like in real life, that's why I see Takahashi-sensei for the amazing teacher he is.
So the show starts around Takahashi-sensei and his fascination with demi-humans, humans who are born with mutations that make them like monsters we know from myth. He meets three girls: a very plucky, hyper, funny vampire girl named Hikari Takanashi, a reserved, studious, well-spoken dullahan named Machi Kyouko, and a quiet, shy snow woman named Yuki Kusakabe. His co-worker Satou Sakie is also a succubus along with being a teacher and she tries her best to be as ultimately reserved as possible to not let her demi nature out and attract men. He develops a strong relationship with all four of these girls in different ways, which may sound inappropriate for a teacher but it's not that kind of relationship, he builds a strong bond between himself and each girl by "interviewing" them. When I say interview all that he really does is let them know if they want to talk to him in his Biology prep room that the door is always open and he's willing to talk to them about any problem they're having. What makes Takahashi a good teacher is he never says that he just wants to discuss demi problems with them, he is interested in that side of them and his knowledge does play into helping them, but he helps them with regular high school problems. Things we all dealt with in high school: rumour spreading, bad grades, uncomfortable crushes, helping them fit in better, needing acknowledgement and encouragement to make it through the days, and needing to be told to knock it off if we acted up. Things all great teachers did for anyone in high school regardless of how different we are from each other. That's an important characteristic about Takahashi-sensei is the way he sees the girls. Hikari's younger sister, Himari, is suspicious of him and asks what he thinks of her sister and the other demi girls. Does her being a vampire make her more important and less human, is there nothing interesting about the human side of her ?? The answer is one that Takahashi put a lot of thought into and one that you can only come up with if you care about people.
"It isn't how you're born that makes you 'like' something. It's how you live with what you are. But that doesn't mean it's okay to neglect an understanding of a demi's nature, the concerns unique to demis are caused by their natures. You can't look at things in only one way, you should look from both angles. If you just see traits unique to demis, you'll miss their individuality. If you only see the human side, you won't understand their troubles. Both are precious. What's important is balance. That's what I think."
True care and thought towards your students, while always putting their best interests in mind, that's what being an amazing teacher is. Tetsuo Takahashi is that kind of amazing teacher.
Between that care of the girls and his undeniable cool around her is also what makes that fourth demi, his co-worker Satou-sensei fall for him. He does everything he can to help her with her own issues too but this is about what a great teacher he is and how honestly they made him out to be a great role model in this anime. There comes a time when something happens and I won't say what because I highly suggest watching this but the girls all make a video for him to show their absolute faith in their favourite Takahashi-sensei.
So cheers on bringing a valuable role model character into the anime world, a teacher that most would be proud to look up to, one that I can personally look at from my own unique point of view and say, "I hope I manage to connect with students this well someday." because that's the goal of teaching: educating and helping your students through all life's hurdles. Good job Takahashi-sensei !!