Shiranai Koto Shiritai no? The Animation

Pla-Pura
When the protagonist's grandfather, who runs a plastic model shop, falls ill, he ends up taking over the business. A regular customer, busty plastic model otaku Risa, appears as a part-timer! Thanks to the strict but reliable Risa, the shop reopens safely, and one day the protagonist discovers a solvent his grandfather made him...