Thoughts on the split-personality plot and who loved who.
White is the functional part of Riya, the part that allows him to fit in with society and go to school, and play the violin. Black is the emotional part of Riya, the one that stands up for himself, that contains his ego, and his ability to love as well as hate. I speculate this divide was based off of a Jedi/Sith distinction because it lines up so well with that, but just complete speculation on my part.
Anyway. The white part of Riya had respect for senpai because of both their relationships with music, the instrument, and performance, but I think it's a mistake to call it love (even though he did say it in the text), because I don't think white was capable of that, he just didn't know what to call it. In the past, full-Riya was captivated by a performance that senpai gave, and meanwhile, after senpai watched Riya's performance, criticized him harshly. Full-Riya knew that his (Riya's) talents were greater, and that senpai was just jealous, i.e., so Riya (pre-split) sassed back at senpai, and that sort of set the stage for white's relationship with him later (e.g., like when senpai kept saying white/Riya "has an ego" even though it was never shown -- senpai just didn't realize there was a split I guess and that the ego went with the part of Riya senpai never saw).
Later, when Riya split, the respect and admiration for senpai's performance went with white/Riya (ex: all the nagging for senpai to get his shyt together, etc), while the hatred of senpai's petty jealousy went with black/Riya ("i hate you" is pretty clear). Because white/Riya couldn't remember anything that black/Riya took with him, he didn't remember the part where senpai was basically a salty jerkhole. This is why white/Riya lets senpai get away with so much (in addition to abuse-victim/stockholm syndrome), and why black/Riya says he hates senpai.
Also, there is the matter that white/Riya's personality was said to be an imitation of his friend Yasui, whom he really misses. Yasui was Riya's first real friend, and the first person who tried to break Riya free of his cycle of abuse, but didn't have the power, as a middle schooler, to do so. And then bad things happened as a result of them running away, and it seemed like white's personality became Yasui so that white/Riya wouldn't have to feel alone even though Yasui was taken from him forcibly. I would say that full-Riya loved Yasui first, never really truly "loved" senpai because full-Riya knew he was a jerk, and that black/Riya loved Atsushi (and white/Riya later accepted this), because the part of Riya capable of love went with black. This was probably why re-formed/Riya told senpai he "loved" him (past tense), because it's an easy word to use, and white/Riya did have some affection for senpai, but it was a completely unhealthy relationship, and full-Riya understands this.
Also, I would suspect the Riya at the end of the manga is actually 3: white/Riya + black/Riya + Yasui. Unfortunately, we're not really given enough time with this final Riya or any time with Yasui to really know for sure. Final Riya is definitely not the zombie his cousin described as his original personality, so yeah.
Thoughts on the split-personality plot and who loved who.
White is the functional part of Riya, the part that allows him to fit in with society and go to school, and play the violin. Black is the emotional part of Riya, the one that stands up for himself, that contains his ego, and his ability to love as well as hate. I speculate this divide was based off of a Jedi/Sith distinction because it lines up so well with that, but just complete speculation on my part.
Anyway. The white part of Riya had respect for senpai because of both their relationships with music, the instrument, and performance, but I think it's a mistake to call it love (even though he did say it in the text), because I don't think white was capable of that, he just didn't know what to call it. In the past, full-Riya was captivated by a performance that senpai gave, and meanwhile, after senpai watched Riya's performance, criticized him harshly. Full-Riya knew that his (Riya's) talents were greater, and that senpai was just jealous, i.e., so Riya (pre-split) sassed back at senpai, and that sort of set the stage for white's relationship with him later (e.g., like when senpai kept saying white/Riya "has an ego" even though it was never shown -- senpai just didn't realize there was a split I guess and that the ego went with the part of Riya senpai never saw).
Later, when Riya split, the respect and admiration for senpai's performance went with white/Riya (ex: all the nagging for senpai to get his shyt together, etc), while the hatred of senpai's petty jealousy went with black/Riya ("i hate you" is pretty clear). Because white/Riya couldn't remember anything that black/Riya took with him, he didn't remember the part where senpai was basically a salty jerkhole. This is why white/Riya lets senpai get away with so much (in addition to abuse-victim/stockholm syndrome), and why black/Riya says he hates senpai.
Also, there is the matter that white/Riya's personality was said to be an imitation of his friend Yasui, whom he really misses. Yasui was Riya's first real friend, and the first person who tried to break Riya free of his cycle of abuse, but didn't have the power, as a middle schooler, to do so. And then bad things happened as a result of them running away, and it seemed like white's personality became Yasui so that white/Riya wouldn't have to feel alone even though Yasui was taken from him forcibly. I would say that full-Riya loved Yasui first, never really truly "loved" senpai because full-Riya knew he was a jerk, and that black/Riya loved Atsushi (and white/Riya later accepted this), because the part of Riya capable of love went with black. This was probably why re-formed/Riya told senpai he "loved" him (past tense), because it's an easy word to use, and white/Riya did have some affection for senpai, but it was a completely unhealthy relationship, and full-Riya understands this.
Also, I would suspect the Riya at the end of the manga is actually 3: white/Riya + black/Riya + Yasui. Unfortunately, we're not really given enough time with this final Riya or any time with Yasui to really know for sure. Final Riya is definitely not the zombie his cousin described as his original personality, so yeah.
This is just my interpretation. (๑•ㅂ•)و✧