From volume 9 to the ending the main focus of the series is shifted to their mother's (Yuka) efforts to separate them, the siblings eventually become so feed up with their predicaments that they reveal their relationship to the guests of their omais right in front of the church, trying to break their marriages with Ren & Kyoka, but their mother still won't allow them freedom; the kids secretly agree to meet in Rome to escape from it all. When Kasumi arrives there she can't find Yoshiki, and gets contacted by the police with the message "we need you to verify the identity of a corpse". Kasumi suffers greatly while gathering strength to even see the corpse, sulking in denial... Funerals for Yoshiki are held in Rome and Kasumi breaks up all ties with her mother & every body else, wanting to stay in Rome permanetly.

As some of you my already have guessed, in the aftermath of the service & when everybody is gone, Kasumi was still suffering about this in the place where she first meet with Yoshiki, at which point he shows kissing her, revealing how he used some aquitances to fake his deadly accident, with that said they finally embrace each other enjoying the knowledge that now no one is standing between them, Yoshiki doesn't miss the chance to kindly whisper "I love you". The next scene is a portrait of their marriage, being exhibited as propaganda in a store that sells bridal items.

Synopsis
It is a very romantic story about love, but it is forbidden to them as they are siblings. They were everyday people with the logical train of thought that incest is unacceptable, until fate played them a trick and cheated them into falling in love.
We read about how they try to reason their feelings for each other, but keeping in mind that the family bond was a new discovery, their heart and mind could not fully understand that they must not be together. But in these situations love burns you whether you do or whether you do not.