Out of curiosity, does anyone know where Riche the cat merchant goes puttering off to during the wee hours (0:00 ~ 4:59 a.m.) of Thursdays? She's not at her shophouse (can even enter her bedroom, which you usually can't if the NPC is sleeping), and neither is she is at the Nameless Beach (her usual haunt on Tuesday 0:00 ~ 4:59). She's not at her other possible locations either (forge, Nameless Beach fishing spot, Southern Beach (at the tent), Western Forest B (near the apple tree), Slime Cave Entrance (near the berry tree with the pepper vines), Mine Ruins: Corrupted Area (near the pool to the east of the map where you see her HCG), Northern Mountain Pass (the area near the center when you trigger her hornet HCG), Northern Mountain Pass: Rest Stop (near the bed)). I even went looking at the four other fishing spots (Eastern Riverbank B, Southern Beach: Fishing Spot, Lakeside B and Slime Cave B1F), but no dice either.
The hint fairy gives no advice during this time (previous or current day), so I presume there's no event or subquest tied to finding her. Is she in a easter egg location somewhere, or is this some bug or oversight left over in the game? I am playing v1.07, but the game still has a lot of minor non game-breaking bugs and/or inconsistencies all over the place, 'though they are mostly just cosmetic or interactions in the game mechanics that don't make too much sense (like upgrading titles at the forge because they're technically considered equipment; say hello to Lilia's title of Non-Virgin +99 for the lulz).
Side note, the author is pretty good at picking out meaningful names for the characters, especially considering they have Western names in a Japanese game. Lilia means "lily" (*cough* yuri, also the flower symbolizes purity and innonence), Sylvia means wood spirit (i.e. a slyph, or fairy) and Riche can mean rich (it's usually a male name in French though). Angelica is the odd one out here at first glance since she's a succubus (and a NEET shut-in), but she's positively angelic and treats Lilia well, giving constant advice and monitoring her health even after going through the trouble of saving her in the beginning (well, unless you stiff her at the ending after going into debt, but ehhh... you really have to deliberately try to fail, so by that point Lilia's suicidally stupid and taking advantage of Angelica's generosity).