Yo-Yoji, introduced in If You're Reading This, It's Too Late, is Cass and Max-Ernest's classmate who spent one year in Japan. He took the Oath of Terces with Cass and Max-Ernest.
From the 2nd book onwards, he joins them on their adventures. He also has a collection of shoes and likes Day-Glo sneakers. He is shown to be musically gifted, playing the guitar very well and being able to recognize certain notes by ear. He studies violin, and later, martial arts, under Master Lily Wei.
Yo-Yoji is in a band with his friends from Japan called "Alien Earache".
If You're Reading This, It's Too Late Edit
When Yo-Yoji first met Cass and Max-Ernest, he was already part of the Terces Society, but kept it a secret to them.
He was constantly hanging out with them, making it difficult for them to keep the the secret that they were in a secret society. In fact, they made it pretty obvious because they aren't good at lying.
He helps Cass discover the notes to the song she hears in her dreams, as well as from the Sound Prism, which spelt out "Cabbage Face". Because of not telling Cass and Max-Ernest about being a Terces member, they thought he was only their friend because he was ordered to be.
This Book Is Not Good For You Edit
In this book, Yo-Yoji was most notably known for eating the chocolate Sr. Hugo made, resulting in awakening his ancestors through him, the Samurai. After Max-Ernest, who didn't eat the chocolate because of his "allergies", found Yo-Yoji, he made Yo-Yoji do many tasks he otherwise wouldn't be able to do, ordering him in Japanese with his decoder. After taming a snake, snatching keys, and fighting Sr. Hugo himself, Max-Ernest and Yo-Yoji finally saved Cass, and they gave him the antidote to the chocolate.
This Isn't What It Looks Like Edit
Yo-Yoji is in Japan for a month with his family climbing mount Fuji. Since he is not with Max-Ernest, he cannot help cure Cass's coma resulting in Max-Ernest needing to do things by himself.
They talk through email twice in the book. The first email is addressing his absence for the next couple of months and the second is talking about how Benjamin Blake went to a school run by the Midnight Sun. Of course to keep things private, they talk in code, which to a stranger looks like gibberish, but to them, it makes complete sense. The code is made similarly in the first book where the word secret is place in the beginning of the alphabet. But instead it is the word Alien form Yo-Yoji's Japanese band.
You Have To Stop This Edit
Yo-Yoji is a very laid back kind of guy. He is considered "cool" by some people in the series, such as Amber, and uses words like "sick" and "yo"
Sometimes, it is seen that he can get quite annoyed. He tries not to show it, but he then ends up bursting.
Yo Yoji is sometimes insecure of his own feelings, much like Max-Ernest. He can act awkward and make things awkward for his friends. At first, Yo-Yoji was very popular, and all the "cool" kids, including Amber, wanted to hang out with him. They don't really so much towards the fourth and fifth book, but Amber still appears to have a weakness for him.
Yo Yoji doesn’t really listen to or care about the “cool” kids, such as Amber, like when he denied her invitation to go to a concert.
The first thing noticed about Yo-Yoji is his shoes. He is always wearing bright neon colored shoes, and he collects them. He is described to have hair like a mop, and in the fourth and fifth book his hair is dyed in neon colors. In the rest of the books, his hair is dark brown with blue or green streaks. He is said to wear skinny jeans, band t-shirts, and neon shirts.
Yo-Yoji is Asian, with Japanese ancestry, as seen in the 3rd book when he started acting like his unnamed samurai ancestor from over 500 years ago.
He is said to be very tall, and in the chapter drawings he is shown to be taller than both Cass and Max-Ernest, and all other people around him, except for any adults.
Yo-Yoji is Cass' second best friend, next to Max-Ernest. He is portrayed as having a crush on her, but is unsure of how to tell her and also scared of what Max-Ernest might think. Cass most likely has the same feeling for him, sure signs being that she always seems to act a little "different" around him as opposed to when she is just with Max-Ernest, and seeming to act a little more spunky then usual and showing off; even ending up hurting Max-Ernest's feelings sometimes and making him feel insecure about their friendship.
At first, the two weren't very close. Cass and Max-Ernest were even annoyed by him hanging around them because they needed to be on their own to figure out the Secret. They soon realize he is actually very helpful and decide that they could use him as a friend.
Later on, when the two are told he was hanging out with them because he was ordered to, Cass and Max-Ernest aren't sure of whether he should stay with him or if they should never speak to him again. However, in the third book, they do end up forgiving him.
In the fifth book, it seems that Yo-Yoji and Cass have grown very close, almost closer than Cass and Max- Ernest. There is a point in the book where Max-Ernest is thinking to himself, talking about how he doesn't feel right around them. Throughout the whole book Max-Ernest seems jealous of Cass and Yo- Yoji, like he's stealing his best friend. Since the book was left on a cliff hanger, it is very possible that Cass and Yo-Yoji become best friends and Max-Ernest is treated like a third wheel. Yo-Yoji even tells his brother he is worse than Max- Ernest, implying he really doesn't like Max-Ernest.
It is implied that he has a crush on Cass. Things like being jealous when he saw her wearing a ring, and his and Cass' pinkies interlocking are some hints towards this. It is also implied that Cass returns the feelings for him.
It is revealed that they dated for a while then broke up in Bad News.
The two do not like each other at first. In the second book, Max-Ernest becomes very jealous of Yo-Yoji believing he is stealing Cass away from him. When Veronica comes running into the room shouting that Amber knows Yo-Yoji likes Cass, it draws the line for Max-Ernest. He starts talking like Yo-Yoji, saying words like "yo" and "sick."
Yo-Yoji is completely oblivious to the fact that Max-Ernest hates him until the three of them go on a camping trip together where Yo-Yoji asks him, "What's your problem?!"
When Max-Ernest solves the riddle to the sound prism, Yo-Yoji thinks he's pretty cool, and even calls him "bro." The two apologize in their own sort of way and find new found respect for each other. They then become friends and grow very fond of each other. It is even said that Max-Ernest feels so lucky to have him as a friend because he teaches him things he never socially knew.
Max-Ernest appreciates Yo-Yoji a lot. He didn't exactly have to hang out with him because all the popular kids wanted him instead. But he chooses to hang out with him and Cass.
Ms. Mauvais and Dr. L Edit
Not much is really known about their feeling towards Yo-Yoji, but they probably hate him too for being on Cass's side.