"Keith is the capture target that was adopted into the Claes family seven years ago for his powerful magic. He’s a handsome boy with flaxen hair and blue eyes, and since he was neglected by his stepmother and stepsister, had a lonely upbringing and became a playboy type character because of it. And when he entered school, his loneliness was supposed to be healed by the heroine and he would fall in love, but to prevent that from happening, Catarina has been pulling him out of his room every day. During this time, without Catarina having to pull him out anymore it turned out that they were always together. Therefore, Keith shouldn’t have grown up lonely this time. This way, the heroine won’t heal his loneliness and he shouldn’t fall in love with her."

Keith is the adopted brother of Catarina, and grows quite fond of her. In the otome game, he is said to be subject to neglect from her, thus making him more likely to fall for someone who gives him recognition. However, since Catarina strove to change her fate, he grew quite close to her. He is also a relatively lead role, but however his child self only appears for a few of the episodes, but if young male voices are more your thing then this would be the role for you. 

https://www.youtube.com/watch?v=lVr_w2B6x5c (up to the 5:00 mark)