Stone statues on オリヴド宮B6F - Blue crystal on the left and yellow crystal on the right. Make all four statues inside the room face down (south-east) to open the gate.

Treasure chest on オリヴド宮B8F - Turn the statues. Clockwise from the top one, Down, Left, Right and Up.

Elf village - Chapter 4. Talk to the faceless man in the pub first. Drop the goddess gauge below 200 and do a random battle. Talk to カウラ. Turn all three crystals to yellow to get in the village.

リンシャ H scene with ヨルマ - Chapter 4. Occurs if you don't give 万里の飾り玉 (obtained after clearing the elf village event) to her.

サリア kidnap event - Occurs in Chapter 5 if ルードン's faction (blue) has fewer points/houses than the red faction. Otherwise he just gives you some money instead.

Recruiting ルー - Get to her sister as soon as possible on 東館B6F. The best way is to ignore most monsters on the map and only fight the ones guarding devices that release the door barrier. She will join レヴィア in Chapter 8 and permenantly joins the party in Chapter 9. You need her to get リザリラ.

レヴィア rape scene - Seems to be related to the female knight rape scene in the mirror world. The number of monsters she runs into in オリヴド宮 (Chapter 3) and the traps on カドラB7F (Chapter 5) may be factors as well.

Saving アビルース - The most important factor seems to be ヨルマ's influence (red factions have at least 20 points/house). Confirmed to work even if someone was raped. Probably need to save ルー's sister. See all five memories (1 = north-east room on B7F, 2 = in front of Celica's statue, 3 = a room to the east of where you fight elf sister, 4 and 5 are in the rooms just before you reach アビルース). Check the bath (top left on B6F). Pick up the shiny item in the magical circle and break the crystal before you fight him.

Recruiting メティサーナ - Beat her first in the mine. Random encounter (視線を感じる) and defeat her twice before Chapter 5. Do her events and defeat her in Chapter 6. She's needed for the idol event on NG+.

Recruiting リザリラ - Occurs in the final chapter? ルー must be in your party. After some events with サリア, random encounter in the mine. Do her quest and beat her.

B10F cannon room - Run straight to the end, dodge the cannon blast on your right. Run back to the other end and take the path on the right. The transparent block should be solid now.

Eushully mascot characters - There are four places to find the books. The first book is in the mirror world on カドラB6F. The second book is on the map where you beat エルモン. The third book is near the entrance going from カドラB7F to B8F. The fourth book is in the mirror reflection room on B7F. Each time you read a book, go back to the mine and random encounter for a mascot character.

EX dungeon - Collect all the books and go to the bottom floor on the last dungeon.