Kurayami no Ryuu wa Kagerou wo Daku

Years after their physical relationship seemingly ended, Kou appears before Risei again as the Family's Wakagashira. Having previously been asked by the Kumichou to look after Kou to ensure that his son lives a regular life, Risei is bewildered by Kou's sudden return and his assignment to work directly under Kou. Risei wonders why Kou, someone who seemed to dislike the Yakuza in the past, became the Wakagashira. Kou then declares, "I did this to make you mine..."

(Source: Core Magazine, translated)