If I remembered correctly, there wasn’t really a relationship. They were blood siblings. The uke from the 2nd couple was in love with the uke from the 1st couple and saw his brother as a nuisance, and they really didn’t get along until the 2nd couple uke died.
oh wow i didn't know that i skipped into the reincarnation part thank u so much!!!
the uke from 2nd couple was in love with the seme from 1st couple! the 2nd couples relationship does develop in the first universe but on a physical level, it develops more emotionally in the time skip/modern universe
someone w a kind heart pls drop the chapters of the second couple in the first universe??? thank you so much