Complex sentence: In the anime series it's revealed by his mother, Kinii, that this is a family trait; according to her, Tofu's father-who looked exactly like Tofu with a moustache-used to behave in the same way when they were dating.
Split into simpler sentences: In the anime series it's revealed by his mother, Kinii, that this is a family trait. According to her, Tofu's father-who looked exactly like Tofu with a moustache-used to behave in exactly the same way when they were dating.