There could be multiple explanations. Maybe it's to protect someone or achieve a greater goal. Or perhaps there's a misunderstanding that's led him to act this way.
I am not sure which anime you are referring to because you did not provide any relevant information. If you can provide more information or clarify the name of the anime you are referring to, I will try my best to provide you with a more accurate answer.
The twenty-eighth and twenty-ninth days of the twelfth month of the Chinese lunar calendar were important days and were closely related to the Spring Festival. In these two days, people were doing all kinds of preparations for the upcoming Spring Festival. The customs of the twenty-eighth year included cleaning houses, putting up couplets and the word "Fu", and preparing steamed buns and other food. The customs of the 29th year included visiting the grave to invite the ancestors to offer offerings, steaming steamed buns, preparing family banquets, and so on. In addition, the 29th was also the day to paste the word "fortune". These customs all implied the removal of the old and the welcoming of the new, and the blessing of good fortune. Therefore, the 28th and 29th were important days to prepare and celebrate the Spring Festival.