Do I still need the booster shot?

According the new information, there is no requirement for the 72 hour pre-test before entering Japan, but it mentioned a vaccine booster requirement. Do I need to take the booster short or not?

Thanks.

Starting tomorrow (September 7), those who have been vaccinated 3 times or more will be exempt from the PCR test requirement. Those who have been vaccinated less than 3 times still need to take a PCR test within 72 hours prior to arrival.

I found the following information on the Embassy of Japan in Australia website for those travelling with children https://www.au.emb-japan.go.jp/itpr_ja/amendedentry.html

Accompanying Children
Children under 18 accompanying their parents are exempted from vaccine requirements as long as they are travelling with fully vaccinated parents. Please note that this exemption does not apply to children under 18 travelling by themselves; they will need to obtain a negative PCR test as below.