A Frog's Child is a Frog - S2.E21

As they continue searching for forgeries, Shūrei and company discover that prices for everyday household prices are slowly rising and ask for the help of Sai Rin. Shin Suou is baffled why Shūrei tries so hard even though she is suspended, while Karin comes back to the Kogaro and recognizes the painting Kochō has put up for display. Karin goes to the place on where the painting is situated from and is found by Ryūki and company. Shūrei and Company arrived minutes later and discover that the place is Shin Suou's home. Shin Suou leads them to a locked building, then opens the door to reveal Banri, Karin's son, painting the forgeries.