Saiki can’t read Nendo’s mind as he doesn’t think. Most people think before they act. In the case of Nendo, he is too much of an idiot which makes it difficult for Saiki to read his mind.
For those of you out of the loop, The disastrous life of Saiki K is an anime based on manga of the same name. What makes it different is the fact that, it has an anti social element to it.
The anime is really hilarious and funny. What makes it enjoyable is it’s simplicity and wittiness of saiki. With that being said, I would highly recommend it if you are used to watching characters like Hikkigaya Hachiman, Oreki Houtaro among others.
Do you have any other questions? Do let me know about it via the comments.
This question was answered after we received an email asking for the explanation of the same.