This trophy is awarded after several scenes with Homhom and Little Meow.
Date - Friendship Level - Location - Description
Year 2, Month 7 until end of game - 0 - Workshop - Random chance of triggering a scene when synthesizing items.
This unlocks naturally, unless you stop synthesis altogether. I will update the exact number of scenes after completing new game+, the minimum is 2, possibly 3.
The trophy unlocks after the scene and the synthesis have ended.