Sailor Moon - Another Story - Part 05 - Chapter 02 - In Search of the Stones - Sailor Venus
1This has the most bosses of the four parts of this chapter.
Though thankfully, you get one of Venus' accessories before fighting anything. You also get the stone very early on, but Venus helps out anyway.
Once in Rias the final hidden puzzle piece is here, in a pot below the shop.
Advancing the story is somewhat frustrating, from what I gathered you have to manually go into the Temple and then talk to specific NPCs until Artemis tells you it's time for the ceremony. The one I missed was the NPC by the entrance to the village, as he has different dialog when you talk to him, compared to when he talks to you as you try to leave.
You're locked into a boss fight in the Temple, Ishtar preferring to use Henchmen for most of this segment. It's easy enough, as they know you haven't levelled up Sailor Venus much yet.
Afterwards you have to find a cure for everyone being turned to Stone (the Hammer item doesn't work?), so a female only village is now the place to go.
Get some levels on the way, and don't enter the castle until around level 10. In here, train until you can kill the enemies in one blow from the front row, and you'll be fine to take on the first boss here, Radina.
Head back to Rias and heal everyone. Ishtar sends ANOTHER henchman after you, and you should comfortably take it.
Doing this frees the villagers from Stone and you can now access the route that was previously blocked by the Stone villagers.
Once on the Ark, be sure to grab the other accessory for Venus, and fight Ishtar, who is easily the weakest of the Opposito Senshi fought so far.