In the shop with a sword icon in Lakeview, you can accept quests from Riley (each time you complete a quest, her belly will grow slightly larger).
Beekeeper Quest: He asks you to eliminate "crazy bees" in the upper-right corner of Ceber Forest. Return to the shop to claim your reward after clearing them.
Slime Quest: In the lower-right corner of the shop, there’s a blue woman who requests help removing slime. Return to Ceber Town and speak to Abby. Then head to the area below Lakeview Town (not the forest) on the World Map to find a cave. Upon entering, Leah will be knocked unconscious by Slime Mom. After waking, Leah turns blue. Clear obstacles by "eating" slimes, then locate Val and Slime Mom in the lower-right corner of the map. Finally, ask Abby to craft an antidote and deliver it to the blue woman.
Missing Fairy: A fairy in the shop mentions her sister is missing in Fay Wood. Enter Fay Wood and go to the left-side map. Find a Waygate on the far left and speak to the Fairy Queen. Return later, and the lower Waygate will teleport you to a maze where each action increases PP by 50. The maze is tricky: follow Right, Down, Left, Up, Right, Right, Right (I won’t admit how long this took me…) to find a fairy with an impossibly large belly.
Imp Mother Quest: Talk to the soldier in the shop. He sends you to purge demons in the Demon Cave at the volcano. Enter the camp with the volcano on the right, then the Demon Cave. A new crack appears in the upper-right corner—enter it, defeat the Imp Mother, and Leah will invite her to the Manison. You can later find her in the Manison’s well.
Rare Demon Egg: Speak to the witch in the shop. She asks you to find a demon egg in Lilith’s Nursery. Enter the map, take the right-side portal, follow the lower-right path, encounter three spores, and retrieve the egg. Going deeper reveals an Easter egg. Return the egg to the witch to receive a Lab Pass. The lab is on the far right of the academy’s first floor, housing a seedbed girl and a pregnant witch.
Riley: After completing all quests, give her a Belly Lotion Supreme (currently only obtainable in the Debug Room—let me know if there’s another way!). She will then produce 20 seeds.