There's something mystical about the unknown. Things you've never seen, things you've only heard about in rumors, and even things whose existence is uncertain... The allure of coming into contact with such objects is undeniable. The value of various jewels and treasures differs. What at first glance may seem to be an ordinary jewel may, in fact, be an incredible magic item... And that's exactly the type of jewel these two magicians were looking for.

Marisa Kirisame is a magician who lives in the Forest of Magic. She has a habit of collecting things, and over the years, she's accumulated a whole range of rare items, which she stores in her house. However, the only one who knows where she's put each individual item is her, and even she's uncertain at times. One peek inside her house is enough to see the importance of keeping things organized. Patchouli Knowledge is a magician who lives in the Scarlet Devil Mansion. She spends her time in the mansion's library reading and researching magic. She herself is sometimes referred to as a library, perhaps because of her vast wealth of knowledge... but it's unclear whether she likes being called that.

It all started sometime in spring when Marisa came across an egg-shaped treasure chest. Wait, no. It actually started when she first tried to open it. By that time, she'd forgotten where and when she'd found the mysterious chest. She figured she'd take a quick look inside to kill some time, but it wouldn't open... She tried scorching it with her mini hakkero and blasting it with a Master Spark, but that still didn't do the trick. She ended up taking it to Patchouli, who, after scouring through countless books, finally managed to get it open. What appeared before the two magicians' eyes were no ordinary jewels... They immediately began examining them and soon lost all track of time.

The Legendary Mokele-Mbembe! There are mysterious objects and lifeforms all around. They're hidden everywhere―from places you visit all the time to places you've never seen or heard of. But while these objects and lifeforms are mystical by nature, it seems they occasionally show themselves for all to see. While Marisa and Patchouli were busy examining the jewels, perhaps someone somewhere else was chasing an entirely different object of mystery. Come to think of it, maybe the jewels being examined were objects of fantasy that had arrived in Gensokyo!

"You gotta be kidding me. So that's what they are!" "Well, at least we had fun figuring it out!" Having finished what they set out to do, the two magicians chuckled as they sipped delicious hot tea. Beside them sat the egg-shaped treasure chest and the jewels from inside it. Marisa and Patchouli had uncovered the secrets of the jewels and unraveled their mysteries, and they now knew exactly how much―or how little they were worth. Egg-shaped treasure in spring... It sounds almost like Easter. Maybe it was no mere coincidence that Marisa stumbled upon the chest when she did. Then again, maybe it was.