Riku pulls down Sora's fly and discovers that the way out of the Realm of Sleep is in the gap where Sora's penis should be. Sora says he is strong enough to survive there so Riku enters basically what is Sora's Vagina and is vomited out by Mickey(The hole exits in Mickey's pancreas).
Once out Riku discovers that he is indeed Sora, but is also Sora's mother so in an effort to keep Sora alive, Riku sends down the dinner Sora neglected to eat before Sora left the islands.
Depressed as to losing his best friend, Riku goes home and bonks Kairi cause she was left in the bed tied up the whole time they were gone and then he gets pregnant.
9 months later Riku gives birth to Sora and the series repeats itself.
Once out Riku discovers that he is indeed Sora, but is also Sora's mother so in an effort to keep Sora alive, Riku sends down the dinner Sora neglected to eat before Sora left the islands.
Depressed as to losing his best friend, Riku goes home and bonks Kairi cause she was left in the bed tied up the whole time they were gone and then he gets pregnant.
9 months later Riku gives birth to Sora and the series repeats itself.