After saving Chun from the Cutters, the young sparrow girl will lead Amaterasu to Sasa Sanctuary. Crossing the torii gate that grants access to the residence, Amaterasu comes up to the inn's gate which is shut tight, only for the guards to send her away, due to Chun still being searched for. Fortunately, the sparrow girl is safe from any danger, and the gates of the Sparrow Inn is immediately unlocked. Proceed inside.
First, head to the elevator on the far side of the hall to the throne room of the Sparror Clan's leader. There, ten treasure chests lies in wait for Amaterasu to open, alongside a thank from the boss. Head downstair and check all the room. In one is a large doll with a blank right eye, so dot in it with the Celestial Brush, and it will open, revealing an item inside. Now, down at the main hall, to the right is a corridor leading to an outdoor bathhouse, whose water has been drained and its attendant praying intently for the water to flow again. Mr. Bamboo then walks into the bathhouse, and upon seeing the attendant's prayers, offered to help. With him, dig through the layers of earth and rocks underneath the hot spring of the bathhouse, and when the bedrock is reached, Mr. Bamboo will signify a block of rock that can be dug through, and by doing so, water will come gushing out, restoring the hot spring. It is then that a constellation of a water goddess appears, which upon completion, grants Amaterasu the Celestial Brush technique of Waterspout. Test it out on the bathhouse attendant, who is running around alight by drawing a line from the hot spring nearby to him, which then the water will follow the line, extinguishing the fire. Test out another ability of Waterspout with the power spring; draw a vertical line on it to create geyser that rises skyward, and can carry Amaterasu on it to reach normally inaccessible locations, in this case, an overhead alcove with a clover. Now, jump down and use the newly acquired technique on the gigantic bamboo fountain nearby, which then the water weighs down its other end and pressing on a pressure plate, opening the gates to Sasa Sanctuary's bamboo forest. Before proceeding through the path, look at the right of the gate for a treasure chest to be dug up, then enter the path beyond the gate. At the second turn, dig near the benches for another treasure chest, and talk to a crying sparrow nearby, who laments about his missing dog, which then the Canine Tracker appears. Follow it further into the bamboo forest to reach a large clearing, with five bamboo trees on the far side. They will alternate in glowing, and use Power Slash on a glowing tree (the Celestial Brush screen has to be brought up during a tree's glow) to cut it down, revealing a canine inside. Prepare for a fight.