WMG / Rascal Does Not Dream of Bunny Girl Senpai

Per wiki policy, Spoilers Off applies here and all spoilers are unmarked. You Have Been Warned.

The world of Rascal is the same as the world of Bakemonogatari

The similarities of both series and their concepts is very striking, to the point that one would be forgiven if one thought that they were in the same continuity. However, what if we go a step further?

The "Adolescence Syndrome", like the Oddities of the Monogatari Series, are supernatural manifestations of the desires of those affected and/or the traumas of their pasts. Therefore, it would not be a massive leap to say that the "Adolescence Syndrome" is actually the work of Oddities from the Monogatari Series. Perhaps not the same as the ones in the original series, but the same kind of creatures.

The Monogatari Wiki describes the reasons for the attacks by oddities as such:

"From a different perspective, oddities often attack people because it's what the people want deep in their subconscious. "Victims" of oddities usually use the phenomenon as means to cope with a problem. Often, one side of "exorcising" an oddity is done by resolving the initial problem at hand."

If you look at the different cases of Adolescence Syndrome in the show, you can see that the description fits the cases. Mai wanted to be out of the spotlight for a while. Tomoe wanted to maintain her social status and relationships and to fix mistakes that would ruin them. Rio holds contradictory desires within her about her body. Nodoka wants to become like Mai to meet expectations. Kaede wants to deal with the aftermath of being bullied. Like the victims in Monogatari, they all have subconscious desires and feelings that manifests as oddities/Adolescence Syndrome.

The reason why it is called a Syndrome, rather than being recognised as "entities" is due to the fact that the characters in Rascal are either unaware of the supernatural (or skeptical such as Rio), and thus would refer to it as a sort of illness or disorder. Furthermore, because the term "Adolescence Syndrome" is used rather than "Oddity", the characters are less perceptive of the oddities because they do not have the concept of an "oddity" to be able to see them, as there are no Oddity specialists who are present to introduce them to the idea.

Indeed, both can be considered correct ways of describing what is happening to the characters. For those unaware of Oddities, it would be entirely within reason to think that they would consider these strange and (relatively) unconnected cases with different symptoms as a "Syndrome", rather than as the work of Oddities.