• Books: Japanisch Schritt für Schritt Band 1 & 2 (self-studies), Marugoto A2 (only in course)
• Vocab: flash-cards
• Kanji: Heisig method ("Die Kanji lernen und behalten 1 - Neue Folge. Bedeutung und Schreibweise der japanischen Schriftzeichen")

DETAILED INFORMATION AND COMMENTS:

1. Well, it all started with anime: it gives you a quite authentic feeling (at least in my opinion) for the sound of the Japanese language (although as I mentioned before anime Japanese is not REAL Japanese, it's like the language of theatre plays, movies or books; that never fully resembles real life communication and conversation).
2. I've acquired a book ("Japanisch in 30 Tagen") when I was about 13/14 because I thought I might go to Japan after my Abitur (graduation) and wanted to start early. I then stopped because I didn't find an organization that would support graduated students for doing a student exchange (rather they offered aupair and work and travel and that kind of stuff).
3. When I had summer holidays in 2017 I once again looked for an organization that offered exchanges for graduates (Abitur). I found Ayusa Intrax (Germany). It was cheaper than the other option (if you want to know the other organizations name (I didn't even apply for their program) contact me). It was perfect. And I could apply for a partial scholarship. So after I applied for the program in general (with or without scholarship) I started learning Japanese using "Japanisch. Schritt für Schritt. Band 1". I also joined a Japanese course at an adult education center. At this center we used Marugoto Rikai and Katsudou A1. Having someone that speaks Japanese as their mothertongue (the course teacher) is very helpful and if you want to become proficient in a language you shouldn't miss out on that.
   
   In Addition to the course and my self studies I also looked for a tandem partner and I actually found one in my town. I put up a notice at a board at the university saying that I was trying to improve my Japanese and that I could help my tandem partner with their German. A nice woman then called me and we became tandem partners meeting about once a week practicing communication.
   
   TIP: Use flash cards that you created in your self studies or from any other source and try making a sentence that contains the vocabulary. Then let your partner correct you and then let them translate the sentence in your language. Very helpful for me and I guess for my tandem partner as well.
4. I visited another course since the old one has finished. The new course's teacher is coincidentally my old one's (I really like her :D), but instead of using Marugoto A1 we use the A2 books (Rikai and Katsudou). Due to my self studies using "Japanisch Schritt für Schritt Band 1 und Band 2" I had no problems regarding the grammar of A2 but there are some vocabulary or Kanji that I didn't know. Moreover I started using "Die Kanji lernen und behalten 1 - Neue Folge. Bedeutung und Schreibweise der japanischen Schriftzeichen" the German version of the Heisig method that uses stories to make you remember how the kanji is written. I find it very effective but as for now (09.07.18) I only learned 184 Kanji with this method and I could not recall all of them right now.