Shin's feed

There is a twin brother
One is jealous because the other twin got all the love
One want their twin brother love

They r both blonde
One is serious
One is friendly to everyone
They exchange identity if they want
No one knew except the glassy boy
They met the glassyboy on library
Glassyboy knew how to distinguish between the twin
Uhh there is 2 side character
One is funky loveable but the other one is not