I, along with a lot of Malaysians who are not JPA scholars, went to a Japanese Language School in Japan for a 1 year course (like a pre-u, but focusing on teaching you Japanese language) before applying to university.
If you already hold a pre-u and do not want to spend 1 year for this course, AFAIK you need to have at least N2 equivalent skill to be eligible for applying to an university (although they do not accept JLPT, you must sit for EJU instead).
The Malaysians that I personally know, ~60% of them went on to study economics/design/art while ~40% went to science/engineering.

Thanks! Now that I know there are indeed universities that do not require EJU. Although I think generally taking EJU is recommended.
By the way, which university are you studying in now? And which language school had you studied in? I was from ABK.

If you want to get admitted into any decent university in Japan you pretty much have to take EJU (and get good scores of course). Maybe there are exceptions, but it is generally highly recommended for you to take EJU. Also, Tokyo U and Kyoto U are notoriously hard to get into. A more realistic target would be from the good private universities in Tokyo area (Meiji U, Chuo U, etc.) or mid-tier public universities (Niigata U, Akita U, Yamagata U, etc.) If geology is from science stream you have to take science subjects in EJU.

Whether you choose PBT or institute from Japan, make sure it is from the designated preparatory course (準備教育課程) list (because you are Form 5 graduate). Both 12-month and 20-month courses from PBT are listed there, but you should probably ask PBT about this to make sure. As long as the course satisfy this requirement, the universities in Japan will not care which institute you went to (or which agent like gogonihon you registered with). What they care is your EJU scores and your secondary school and SPM grades. EJU matters the most so don't get discouraged by bad SPM result. Just make sure you study properly from now on and do well in EJU.

PBT would be much cheaper due to the living cost in Malaysia vs Japan.

In PBT's website, they recommended students who intend to enroll in a university to opt for the 20-month course. Most language institute in Japan would recommend this too because 12 month is a bit too short to prepare properly for EJU and master Japanese language, especially if you are learning Japanese language in Malaysia (PBT), because obviously the environment is "less Japanese" (you are still in Malaysia after all) and it is harder to immerse into the study of the language. However, some institute do provide the 12-month option.

The one institute I would highly recommend (if you want to go to a language institute in Japan) is ABK Institute. They are very experienced in handling international students' education affairs and they do provide a 12-month course of high quality. However, the 12-month course commences on April so you should start applying now if you want to enroll in the coming April (no, you do not need to wait for your SPM result). If you are interested about ABK's course, you can inquire LUJEC (they are in KL). (*Don't worry, I am not a marketing agent. I am just recommending them because I personally had good experience with LUJEC and ABK)

Summary:
You should probably do EJU. Go to PBT or go to a language institute in Japan, it does not matter as long as it is a 準備教育課程. PBT is cheaper. Language institutes in Japan provides better environment for studying Japanese language. 1-year course exists in some language institutes in Japan (I recommend ABK for this), but 1.5-year course gives you more time to prepare properly. Do well in your EJU if you want to get into a decent university in Japan. Start applying (or asking PBT/LUJEC/whatever agent of your choice) NOW if you want to enroll in the coming April.

This post has been edited by Kurogane___: Dec 15 2019, 03:02 PM

1. Aim for public universities. In many of them, around half of the international students enrolled get 100% tuition fee reduction (so you only need to pay for living costs, which can be covered by doing part time job). There are also some scholarships available in Japan but most of them are in small amount (they are only designed to encourage you, not to cover your living cost or tuition fee). The ones that fully cover your living cost and/or tuition fees are very difficult to get and usually require interview in Japan. I am not sure about scholarships provided here in Malaysia, but I assume they are hard to get as well.

2. You will probably rent a room nearby. But I do not come from PBT so I am not sure about this.

3. Not much we can say as they are your parents, you probably know them better than we do. To be perfectly honest, I won't even recommend studying in Japan if financing is an issue. But if you can demonstrate your responsibility and grit through your willingness to do a part time job to finance yourself, they might get convinced.

4. Part time job. Some international students do more than 28 hours weekly of part time job in Japan (which is illegal) to finance for both living cost and tuition fee, but I won't recommend this for obvious reason (it's illegal). But if you get 100% tuition fee cut (as I stated in 1.), living cost alone can easily be covered by 28 hours of part time.