Good day to all the girls who looked in, and therefore not indifferent to tsundera (well, boys too, why bother with trifles here). Previously, it was extremely unclear to me where so much love for such characters came from, most often they caused me either dislike or indifference. But over the years spent watching anime, you get used to this kind of thing and many moments become more understandable.
Well, let's discuss it.

To begin with, let's refresh our memory of who tsundere are in general and what they are eaten with.
Tsundere — from yap. tsun-tsun "angry, sharp" and yap. dere-dere "loving, caring" — characters of this type initially behave narcissistically and selfishly, treat others either coldly and arrogantly, or behave aggressively and bullying, but throughout the plot reveal a bright, good the side of character, in most cases — under the influence of the object of love. They initially shy away from this very object and make it clear in every possible way their aversion to it, but sooner or later the disguise collapses. This is the classic definition of a tsundere.

Well, then, of course, you will ask: So what's attractive about it? It's all about the "gain-loss" effect. Its essence lies in the fact that an increase in the level of positive, rewarding behavior on the part of another person has a greater impact on the individual than an unchanging, invariant "reward" coming from the same person. Therefore, if we consider sympathy as a reward, then the person whose sympathy for us will increase over time will please us more than the one who has always sympathized with us. This is true even if the amount of "rewards" was greater on the part of our "regular fan".

Also, do not forget: in order for the effect of gains and losses to work, two important conditions must be in place. The first is that not every sequence of positive or negative statements leads to gain or loss – it must necessarily be logical, indicating a real change in attitude. The second condition is that the change of attitude should be gradual. The reason is clear: a sudden change in the views of another person will cause confusion and suspicion, especially if such a change does not have serious factual grounds.

Therefore, how slowly and gradually the character's attitude changes so fascinates the viewer. We understand that kindness and care can hide behind rudeness and coldness. It's like they're trapping us in their trap, and we don't mind getting caught in it. By the way, some people also like the fact that the characters show their "dere" side only to the object of adoration, for the rest they remain more restrained and detached.