"I buy cute clothes in Harajuku on the weekends."
True. The reason why Duolingo should introduce Kanji and extend this tree is because of the nature of Japanese sentence. Using Kana would be okay, but given the fact that Japanese has no spaces between the words, you create an almost undecipherable text (as in 75% or more in this tree). I’ve seen in one of the previous exercises when the adjective inflection was introduced that the sentence “I like cats more than dogs” was written entirely in Kana.... or いぬよりねこのほうがすきです。そうだったよ、叫びたかった。
My opinion is that Duolingo should extend their tree because there is a lot missing (Potential Form, Conditionals, Causative, Passive, making contrast between sentences, expressing regret...) and the Tips & Tricks (on Android there is one for each lesson) NEED to be expanded with more notes and directions. 90% of time I spent on looking things up because of the lack of material.