Tourou no Ori, Aka no Theatre Recommendations
Nearly identical dynamics between our MCs. On one hand we have a mature, dark haired employee of a wealthy estate, who has his eyes set on a certain personal goal. On the other hand we have a young and impressionable man, who's been in the 'care' of said employee ever since his childhood. This man heavily influences the life decisions that the young boy makes, in order to achieve his goals. But on the way, he ends up developing feelings for the boy as well, leading to the two having a twisted *and* open relationship.