9. Toradora - Taiga Breaking Her Promise
Taiga Aisaka spends the entirety of Toradora trying to express her feelings to and win over Yusaku, a friend of Ryuuji. She also helps Ryuuji do the same, only towards her friend Minori.
Over time she gradually softens and begins to see Ryuuji in a romantic light. It is only natural that after spending so much time together and caring for one another that they would develop feelings for each other. Even the coldest of tsunderes will thaw after that much bonding.
So, when Ryuuji and Taiga decide to elope together, they are more than ready to marry and proclaim their love for one another. However, instead of continuing to run away and simply doing as she wishes, Taiga faces her problems by choosing to return to her mother.
As she is already estranged from her father, it is best to mend what relations she can and stabilise her family life first; better to figure things out properly, rather than impulsively marrying at such a young age. She understands the importance of maturing first and foremost.
With great difficulty, Taiga decides to cast aside the feelings she has finally let free after all this time and even hurt her love Ryuuji in the process - all of this was for a better future.