This is missable.
The first time you head down the T-junction in Sakuragaoka, a cutscene will initiate in which Ryo encounters an old lady who is having trouble finding her friend's house. Ryo offers to help, telling the old lady to wait for him in the park just up the road.
After the cutscene ends, turn around, head straight up the road to the house almost directly opposite the park (the one with the closed gate), zoom in on the little silver sign (which reads "Yamamoto") on the wall to the top-left of the gate with
, and press
Once Ryo confirms this is the correct house, enter the park, approach the old lady sitting on a swing, and Ryo will escort her to her friend's house.