These are a Hana's series: Hana no Mizo Shiru and its sequel: Hana no Migoro ni. Then the last sequel-prequel or spin-off: Hana no Miyako De
1 - Hana no Mizo Shiru
2 - Hana no Migoro ni
3 - Hana no Miyako de
1 - Hana no Mizo Shiru
2 - Hana no Migoro ni (The best!!!!so beautiful)
3 - Hana no Miyako de
1 - Hana no Mizo Shiru
2 - Hana no Migoro ni
3 - Hana no Miyako de (this one): A sequel or Spin-off of Hana no Mizo Shiru and Hana no Migoro ni. (But it occurred way before the storyline of Misaki Shouta and Arikawa Youichi).
A REALLY SAD SAD STORY T_T (they didn't end together) so heartbreaking {But finally I understood that it was needed to happen for the existence and developing of the Arikawa and Misaki's relationship}
Junjou Romantica