Bunkichi

To initiate the Old Couple Social Link, the Protagonist of Persona 3 must speak to Bunkichi and Mitsuko on April 25th or later, then bring them a leaf from the Permission Tree at Gekkoukan High School. This will begin the Hierophant social link. From then on the protagonist may visit Bunkichi and Mitsuko at their bookstore at Iwatodai Station on Monday through Saturday.
 
In every social link event, Bunkichi will force an item onto the protagonist. This item is almost always a minor item to be used in Tarturus. As the social link progresses, you learn of the couple's daughter, a former teacher at Gekkoukan High School who died in a car crash. Bunkichi and Mitsuko reveal to the protagonist that the persimmon tree was planted in memory of their son.
 
Later in the Social Link the couple learn that the school plans to cut down to persimmon tree in order to add a new wing to the school. While at first the couple are stricken with grief and anger (Even once mistaking the protagonist to be the leader of those who want the persimmon tree to be cut down), they eventually come to accept that cutting down the tree is for the best. Stating that their son would prefer that a new wing of the school is to be built, and agreeing that education is more important than memories.
 
At the end of the Social Link, the couple is thrilled to learn that the tree will only be moved to another part of the school, instead of being cut down. As a sign of their friendship and gratitude for the protagonist, they give him a persimmon fruit, a fruit from the tree.
 
Maxing the Hierophant Social Link unlocks the Persona Kohryu.