Wrong. The only things written only in Hiragana are intended for 5 year old readers and they still have a couple kanji in them. If you're only intending on speaking Japanese then you might be able to scrape by only learning hiragana, but you'll miss out on many nuances and cultural aspects of the language by not indulging in learning kanji.

As you may know already there are three types of writing systems the Japanese use. Hiragana (ひらがな) Katakana (カタカナ) and Kanji (感じ) Kanji is used thoughout most sentences, but the Hiragana can be used to pronounce them (especially when learning new Kanji). In most Japanaese learning books, the Kanji (and sometimes Katakana) is normally shown with Hiragana at the top in brackets to allow you to pronouce it. For example... (わたし) 私　　　　 watashi = me Hiragana is the most basic part of the Japanese language and it can be very useful when speaking Japanese but not so much when reading or writing it so make sure you learn your KANJI SYMBOLS!

no, you must memorise Hiragana, Katakana and Kanji

I hate to break it to you but.....Kanji is required to know/use or the Japanese sentences would be monstrously long! Some words are only written in Hiragana but some words that sound the same need to be differentiated with Kanji, as well. Keep in mind, however, if you were able to learn the Hiragana syllabary, Kanji is not THAT hard (and you're on iTalki for help!) がんばってねください！