Upvote:3
Timatic tells us:
Visa
Visa required.
TWOV (Transit Without Visa):
Passengers with a confirmed onward ticket for a flight to a third country on the same calendar day. They must stay in the international transit area of the airport and have documents required for the next destination.
Passengers transiting through Tokyo (HND) or Osaka (KIX) with a confirmed onward ticket for a flight to a third country within 72 hours. They must stay in the international transit area of the airport and have documents required for the next destination.
Passengers with a passport and a confirmed onward ticket to a third country within 72 hours can obtain a Shore Pass on arrival if there are no connecting flights on the same calendar day. They must not be subject to entry restrictions and they must:
- have documents required for the next destination; and
- have proof of sufficient funds to cover their stay; and
- arrive at and depart from an airport or seaport located within the same group below.
- Group A: Airports: Narita (NRT), Haneda (HND), Nagoya (NGO), Niigata (KIJ), Komatsu (KMQ) and Yokota (OKO). Seaports: Tokyo, Yokohama, Niigata and Nagoya.
- Group B: Airports: Osaka (KIX), Nagoya (NGO) and Komatsu (KMQ). Seaports: Osaka, Kobe and Nagoya.
- Group C: Airports: Fukuoka (FUK), Nagasaki (NGS), Kumamoto (KMJ), Kagoshima (KOJ), Naha (OKA) and Kadena (DNA). Seaports : Hakata (Fukuoka), Shimonoseki and Naha (Okinawa).
- Group D: Airport: Chitose (CTS). Seaports: Tomakomai, Otaru, Hakodate and Muroran. NOTE: NRT and NGO are not open for 24 hours. Passengers cannot stay overnight at transit area.
You don't qualify for either of the first two TWOV exceptions (you're not staying in the international transit area). You apparently don't qualify for the third TWOV exception because your connecting flight is on the same calendar day (!).
So IMHO do you do need a visa in your situation. I can't find any relevant details on the Japanese Ministry of Foreign Affairs site so I don't know the official requirements.
Note that visa issuance is currently very limited. Not sure if they would actually issue this type of visa at the moment. Also it seems that even for countries which usually do not need a visa, entry without a visa is not possible at the moment.
Your best bet is probably to contact the Embassy of Japan in Vietnam, they would likely be the ones most aware of the current situation.