No.3 Hell of Mirrors

「カガミジゴク」
The Hell of Mirrors is the third of the Seven Mysteries. It was the fifth School Mystery to be introduced in the series. It first appeared in Volume 6, after Nene was pulled into its boundary by the disembodied hands as per Mitsuba's order.

The third Mystery's representative has the ability to reflect the hearts of those who wandered inside it. Those who are pure of heart will be able to escape without trouble, otherwise, the mirror will change its appearance to reflect one's deepest fear, beckoning its victim to stay forever. It tortured Nene by telling her that she has radish legs. For those without memories, the mirror appears blank.

The School Mystery desires to trade places with the living, allowing for the mannequin who manages to capture the human's soul to replace them.

As he and his minions attacked Nene and Mitsuba in order to kill them and take their identities, Tsukasa appeared and saved them. Tsukasa then killed Number 3 and forced Mitsuba to eat his heart, in order for him to take the place as the new representative of the 3rd School Mystery.

The aspect the Third School Mystery oversees in Kamome Academy is currently unknown.

Boundary
The Hell of Mirrors' boundary is an expansive, multileveled space, with many mirrors decorating the walls. It is said that the boundary changes its nature according to the people who enter it, when the person looks into the mirrors, it will reflect the person's fear. Thus Hanako and Kou couldn't carelessly enter, in case it becomes more dangerous when they do.

The Yorishiro of Mystery No.3 is an unknown object suspended high above on the boundary's ceiling.

Due to memory loss, the Yorishiro have not changed for the new representative of the third mystery.

The Rumor
Japanese=・・・知ってる？

七不思議三番

カガミジゴク

鏡の向こうの不思議な世界

そこには迷い込んだ人の心の

映し出す鏡があるの

とっても心の綺麗な人勇敢な人なら大丈夫

無事に元の世界へ戻れるでしょう

だけどもしほんの少しでも

醜いところや怖いものがあるなら

鏡はそれを映し出し

世界はたちまち地獄に変わって襲いかかってくるでしょう|-|Official English Translation=...Did you know?

No.3 of the school's seven mysteries...

...Is the Hell of Mirrors.

It's a wonderland on the other side of the looking glass.

There are mirrors there that reflect...

...The hearts of all those who wander inside.

Someone with a beautiful or brave heart will be just fine.

They'll be able to return to their world without any trouble.

But if their heart contains even the smallest bit...

...of ugliness or fear...

...The mirror will reflect it...

...And the world will change instantly, becoming a dark hell to attack its victim.