Book Recommendation: Lonely Castle in the Mirror

Posted On March 23, 2026

Hi Readers! When I love a book, I can either write an unending review or I’m at a total loss for words. With The Lonely Castle in the Mirror, it’s the latter, and yet, here I am with my ramblings. This book was on my TBR for years, and I so regret it. I should have read it a long time ago, so if you have been doing the same, well, consider this as a sign and read it NOW! Here’s the spoiler-free review, except for a specific section at the end!

~~GOODREADS DESCRIPTION~~

Seven students are avoiding going to school, hiding in their darkened bedrooms, unable to face their family and friends, until the moment they discover a portal into another world that offers temporary escape from their stressful lives. Passing through a glowing mirror, they gather in a magnificent castle which becomes their playground and refuge during school hours. The students are tasked with locating a key, hidden somewhere in the castle, that will allow whoever finds it to be granted one wish. At this moment, the castle will vanish, along with all memories they may have of their adventure. If they fail to leave the castle by 5 pm every afternoon, they will be eaten by the keeper of the castle, an easily provoked and shrill creature named the Wolf Queen.

Delving into their emotional lives with sympathy and a generous warmth, Lonely Castle in the Mirror shows the unexpected rewards of reaching out to others. Exploring vivid human stories with a twisty and puzzle-like plot, this heart-warming novel is full of joy and hope for anyone touched by sadness and vulnerability.

~~TRIGGER WARNINGS~~

Bullying, sexual assault, cancer, suicide.

~~THOUGHTS~~

Have you ever felt utterly alone?

Like no one ever understood your pain, your trauma, your hardships?

Like no one understood you?

Lonely Castle in the Mirror is for all those people who have felt that way.

Kokoro, an 8^th grader, stopped going to school. Then one day, the mirror in her bedroom glistened, so she touched it and went inside it to a castle. In this castle, she found 6 other people, who were just like her, with their loneliness, pain, trauma and hardships. These seven kids, though seemed outwardly normal to each other, each had a story of their own which brought them to the castle, which is governed by the Wolf Queen.

In the initial 30% of the book, we understand Kokoro’s life. She was a carefree child but after one terrible bullying incident at school, she just couldn’t go to school anymore. She is a sensitive and gentle soul and after reading how she had to fight to survive each day, your heart can’t help but break for her. You’ll want to give her a hug and tell her everything will be okay. Even after discovering the castle, it takes her the longest time to make friends because one casual off-handed sentence throws her 10 steps away and back into her shell. It could be someone looking at her the wrong way, or feeling like everyone is out to get her, or feeling like someone’s behaviour changes just because she’s around. The worst of them is the feeling that everyone else is moving forward but she’s still stuck in the same zone, and always just one incident away from a complete breakdown.

With very slow steps, she starts talking to two boys, Subaru and Ureshino, and after a while to the two girls, Aki and Fuka, and then eventually with Masamune and Rion. She understands how they didn’t have it easy either. If anything, our sensitive Kokoro also becomes an empath and fins real friendship with these kids, something she never had in the real world.

The Wolf Queen had brought them together to the castle and given them one year to stay there. In that time, they were to find a key and whoever does gets their wish fulfilled. It becomes much more interesting in the last 30% of the book. I won’t spoil it because it truly was mind-blowing. The reason I loved this book was because of how wonderfully emotions are written and how they are felt by the readers. The second reason is the entire magical realism aspects and the ending to the book. I have rated Lonely Castle in the Mirror by Mizuki Tsujimura, translated by Philip Gabriel at 5/5 stars!

~~SPOILERS AND ENDING EXPLAINED~~

Throughout the book, I thought this was obviously going to be about parallel lives. There were a few hints now and then. When they all decide to meet in the real world school, they uncover it all. How much would it suck to finally have friends but all of them were in different parallel universes? But, only towards the end, we understand what it was all about. They did not live parallel lives. They lived in the same life, just at different times! Their age when they were in the castle was around the same, but they were all born in vastly different years, each with the gap of 7 years between them.

Subaru lived in 1985.

Aki lived in 1992.

Kokoro and Rion in 2006.

Masamune in 2013.

Fuka in 2020.

Ureshino in 2027.

Each had a gap of 7 years between them, except for 1992 to 2006. This is when Rion understands that the Wolf Queen was actually his little sister who was born in 1999. She created the whole castle universe for her little brother Rion who was only 5 years-old when she passed away. So, when the castle was about to disappear forever, he asked for one wish which was to remember everything that happened there.

It was an emotional rollercoaster of a book with a lot of heavy themes and which will definitely make you cry.

Until next time,