If you're starting to feel like every anime character is a selfish jerk who is just looking out for number one, it may be time to give selfless anime characters some attention.
Some of these selfless characters are sacrificing major things like their personal safety, their ability to remain in society, or even their ability to exist in human form. Others simply put others first and love to help out, without ever causing themselves to suffer.
Whether a character is more like Itachi Uchiha, who killed his entire family and then exiled himself in order to save his brother's life and prevent war, or more like Phichit Chulanont, who just wants to bring happiness to his country through figure skating, these characters embody the spirit of giving.
Alphonse Elric is always willing to help out a person in need, but he truly shows the depths of his selflessness when he gets the opportunity to reunite his soul with his body after spending years trapped in a suit of armor. Because Alphonse is in the middle of a battle, reuniting with his severely weakened body would put him - and the rest of his comrades - at a severe disadvantage.
For the sake of the greater good, Al decides to stay in the suit of armor, even though for all he knows, he'll never get another chance to get back to his body.
Izuku Midoriya wants to be a professional hero more than anything in the world. While he is partially motivated by a desire to be as cool as his idol All Might, his main goal is to save people who are in danger. It doesn't matter how weak he is in comparison to his opponent, he'll rush into any fight and put his life on the line if it means ensuring someone else's safety.
When he's not rescuing Bakugo from sludge monsters or helping Iida defeat a vigilante criminal, he's helping others emotionally at his own expense. During the Sports Festival, Izuku competes against Todoroki. When he sees that his classmate is too emotionally distraught to do his best job, he encourages him to work past family issues to fight to his full potential - even though that means that Izuku is a lot less likely to be able to be able to win the fight.
If you knew that you were going to die within a year, how would you spend that time? Most people would want to satisfy their personal desires - maybe eating every food they ever wanted to try, going on awesome vacations, or having a love affair. Koro-sensei has something different in mind.
Instead of indulging himself in the time he has left and then heading off to outer space to explode, Koro-sensei uses his remaining year of life to teach a bunch of middle school kids how to rebuild their self-esteem and become competent in all areas of life through the fine art of assassination.
Tohru Honda's mission in life is to care for and help other people. At first, that person was her mother, who worked full time and needed her daughter's support to run the household. After her mother's death, she's so concerned with not being a burden that she moves into the woods rather than live with relatives.
From there, she's absorbed into the dark and mysterious Sohma family, who she immediately sets about not only cooking and cleaning for but also attempting to heal their complex and numerous emotional problems. Part of Tohru's journey is learning to prioritize her own needs once in a while, rather than endlessly pouring out empathy.