Sunshine After The Rain

Kocher High School is ruled by wealth and power, and above them all stands C5 - a group of five second-year students from the richest families in the school.
Their leader is Chaikamon Phayu, The heir of the Chaikamon Group and relative of the legendary Paramaanantra family. He was Idolizing Thyme Paramaanantra and the former F4 leader, Phayu revives their legacy once again through C5.

Rain Nuttarat entered Kocher determined to stay invisible after his family's sudden downfall.
But his peaceful school life ends the moment he punches Phayu in the face.
Just like history repeating itself.
Ten years ago, Thyme Akira Paramaanantra was once punched by the love of his life, Gorya, in the very same school.
And now, slowly but surely...
Phayu finds himself falling for Rain too.

Unfortunately, there's one problem.
Rain already has a fiancé.
And worse
his fiancé is Hase Yang, Phayu's lifelong rival.

note:
Inspired by the Japanese drama Hana Nochi Hare, the sequel of Hana Yori Dango.
and yes Hase Yang was Hase Tenma from Hana Nochi Hare ^.^