"He’s the taciturn, expressionless son of the prime minister, and also a capture target. With black hair and eyes, and a perfect doll-like face, he’s a handsome boy with a devilish charm that can even capture men as well as women with his unique atmosphere. Just like the others, in the game settings, Nicol wasn’t supposed to have any contact with Catarina Claes at all, but after Catarina became friends with his sister by chance, he also started coming over to her house almost every day. He was taciturn and expressionless like usual, and only spoke up when he had to, but his devilish charm seems to be increasing in strength every year."

As stated above, Nicol wasn't supposed to have much of a relationship with Catarina, but through their few meetings, even the seemingly cold, expressionless Nicol has succumb to her. While he is considered a lead character, he doesn't have as many lines as the others, and the same goes for when he was young. This is for the people who want in, but don't want that many lines.

https://www.youtube.com/watch?v=xsMD1MhCfl4 (up to the 1:15 mark.)