Best way to put most Japan spend on a US card while earning ¥ income? (CSP downgrade → CSR SUB? Amex/ANA? VX?) + transfer fee math

Curious if anyone has tried to run the majority of their spending in Japan on US-issued cards, while being paid in yen.

Context:

• Living in Japan, earning ¥

• Want to charge as much day-to-day spend as possible to a US card (no FTF)

• We travel a lot: \~4 international round trips/year as a family of 3 (Asia + Europe + US)

• Assume \~1% friction to get money back home (Wise, etc.) — I’d want that included in the math

Current setup / options I’m considering:

• I have a Chase Sapphire Preferred and I’m eligible to downgrade to a Freedom, then potentially go for a Sapphire Reserve SUB

• Also wondering about an Amex setup: does it make sense if I care about ANA (MR → ANA), or is acceptance / practicality in Japan too annoying?

• Or is something like Venture X just the “easy button” for overseas spend + travel perks?

Questions:

1.  Has anyone successfully made a “mostly US cards in Japan” setup not feel like a hassle (acceptance, mobile wallet, etc.)?

2.  When you include \~1% transfer cost (Wise) to true-up USD, does that change what’s optimal (e.g., 2x vs 3x vs category multipliers)?

3.  If you’ve run the numbers: CSR vs Amex MR (ANA) vs Venture X, what actually wins for a Japan-based spender who flies internationally a few times a year?

4.  Any specific cards that play especially well with Japan contactless / Apple Pay and everyday merchants?

Would love input or “here’s what I ended up doing and why.”