The second male protagonist isn’t playable in the current story and is mainly introduced for establishing a significant portion of the past that ties into the main events of the story. His story, set 10 years before the main timeline, serves as a setup for future events and builds the foundation for key plot elements that will directly affect the main MC. While his arc is important, it’s designed to be brief (about 4-5 episodes in total) and will conclude soon. The primary focus will remain on the main MC moving forward.
As for your second question, yes, some of the women the second male protagonist has previously interacted with will cross paths with the main MC in the current timeline. However, they will not be available as romance options for the MC. Their roles in the story will be tied to the broader narrative, providing additional depth and connections between the two timelines rather than serving as potential love interests.