Confused about tax-free items and customs when leaving Japan

I don’t fully understand the customs process when it comes to purchasing goods in Japan and leaving with them – is there a limit to how many items I bring back, or the overall value of those items totaled? Can I put them in my checked bag? I have been told to not tell customs I have over $1k worth of stuff, no matter how much I spend, but that doesn’t make sense to me. I was also told a lot of the items should be in the carry on only, which sounds a bit challenging if true. I plan to save all receipts, but I’ve been googling and the process is relatively unclear due to the differing opinions online and inconsistent travel regulations listed