Past-Senger

Time travel. In the finale the age difference between the main characters is more than 20 years. The main character loves his friend's son.

Both dramas are BLs that deal with men who are thrown into a different reality.
Both dramas focus on the comedy and romantic aspects instead of the science behind it.

Both of these are boy love series, and the plot involves romance and time travel (in this case both times jump into the future).

Somehow the protagonists in both of these series time warp to the future. The Past-Senger primary story is bl. The Warp Effect's bl is a side story.