Moving Italy -> Japan (April 2026): Best way to handle IBKR Europe portfolio and NISA setup

​Hi everyone,
​I’m currently living in Italy and will be relocating to Japan in April 2026 for a new job. I’m looking for advice on how to transition my small investment portfolio efficiently.

​Current Situation:
​Broker: Interactive Brokers (IBKR) Europe.
​Assets: Vanguard World ETFs (UCITS).
​Portfolio age/size: Started ~1 year ago, relatively small balance.

​My Questions:
​IBKR Migration: When I change my tax residency to Japan, what happens to my IBKR Europe account? Can I simply update my address, or am I forced to liquidate/transfer?
​ETF Compatibility: Can I keep my current Vanguard UCITS ETFs while living in Japan, or do they become a tax/compliance headache? Should I consider selling them before moving and starting fresh?
​NISA Strategy: I plan to open a NISA account once settled. Given my portfolio is small, would it be simpler to sell my European assets and "restart" my investment plan directly within the NISA framework in Japan?
​Logistics: Is an in-kind transfer from IBKR Europe to a Japanese broker (like Rakuten, SBI, or IBKR Japan) even possible for a small portfolio, or is "cash out and reinvest" the standard path?
​I’d appreciate any suggestions on the most tax-efficient and simplest way to handle this transition.
​Thanks in advance

by Feeling-Lecture-906