Is there an AI learning function in Yaraku Translate (personalized translation)?

Yes, there is.

 Yaraku Translate's personalized translation is a machine translation that is personalized for each user based on the machine learning results using registered phrases.

When you register your translation to Phrases, regardless of the engine use, our platform is using it for individualized machine-learning, so it will be automatically edited next time similar expression appears.

Machine learning is based on words and phrases, and it takes into account the before and after context.

Therefore, depending on the context, it may not work, and it may not be the same expression every time. 

Please visit the Features page under article about AI translation for more information.