Can you recommend some high-end jewelry that can be purchased with a budget of ¥200,000–¥300,000?

Seeing something online and actually trying it on are two very different things. If the questioner doesn’t think it’s cute, there’s no point, so if you live in Tokyo, I’d suggest looking around areas like Ginza or Omotesando, where many brand flagship stores are located. Whether it’s Bulgari or Tiffany, you can just walk in and say, “I’m looking for something in the ¥200,000–¥300,000 range,” and they’ll show you some options. I recently bought Tiffany’s Bone Cuff for ¥210,000. The cool silver shining on my wrist in the summer is beautiful, and I love it. I recommend it, but depending on your face type and body frame, it may not suit you, so try it on in person.

I think what matters is choosing what you personally like, so in your case, I’d say Boucheron.