Does the second story have it's own manga

it's the story that start the Rules universe

see timeline here 1) Please (5 chapters)
-- Kiss (MIYAMOTO Kano)
-- Kiss After
2) Skies **
3) Hydra (ch1-6)
-- Blue Film First (after Hydra ch8)
-- Hydra dj - Heavenly (between Hydra ch9 and ch10-11)
-- Real Thing
-- Hello Again
5) Lovers and Souls
6) Fragile **
7) Vanity **
8) Dreamer's high **
13) Rules volumes 1 & 2
14) If Winter Comes, Can Spring Be Far Behind? **
15) Rules volume 3

You can also just skip the doujinshi (--) and follow the number.

16) Rules dj - Song Birds
17) Another Day on the Planet (booklet)
18) Rules dj - Double Trouble
19) Rules dj - Overload
20) Rules: 2nd Season