Sean Lynn's side win in Kumagaya City to earn third victory in four matches of WXV Global Series; Japan have lost all four matches so far
Nel Metcalfe try gives Wales early lead before Moe Nagaoka registers home side's only try
Visitors extend lead through Kelsey Jones and Amy Williams tries along with two Lleucu George conversions
Sisilia Tuipulotu scores Wales' fourth try before Williams bags her second of the contest to seal an impressive victory
HT: Japan 5-19 Wales
Catrin Edwards
Former Wales prop Catrin Edwards on Radio Cymru
These are the sort of moments that make a great team.
Forwards carrying the ball and Seren Lockwood sees the gap. A simple but effective try and it's lovely to see Amy Williams score.
Japan 5-19 Wales
Poor by Wales, who are caught napping at the restart.
Japan dink a drop-kick and regather but they are then pinged at the breakdown AGAIN.
George boots it off. Healthy lead.
Amy Williams
Watch as wing Amy Williams gets Wales' third try
That's a clever score.
Wales put the pressure on with a driving line-out and then stay patient.
Seren Lockwood waits and then bursts down the blindside to put wing Amy Williams over down the left.
George hits the post with her conversion but this is a good lead with the restart to come.
Japan 5-14 Wales
Siwan Lillicrap
Former Wales captain on BBC Radio Wales
This is where Wales have got to be really careful.
It's a nine-point game, you can't allow ill discipline or a catalogue of errors to creep in. They've got to have urgency and got to keep focused.
Japan 5-14 Wales
Japan put the heat on Wales.
Lleucu George is charged down and the visitors scramble, then are relieved to be given a penalty at the breakdown.
Wales are a score clear but need to work a bit harder to get real daylight because the Japanese are feisty opponents.
Japan 5-14 Wales
Carys Cox gets Wales on the front foot with a line break but the moves frustratingly comes to an end, with the pass to the right going wrong.
Lock Branwen Metcalfe fails to find sister wing Nel Metcalfe.
Can't put that one down to being a new combination.
Japan 5-14 Wales
Philippa Tuttiett
Former Wales international on BBC One Wales
Kate Williams again, player of the match last week.
She is absolutely everywhere.
Japan 5-14 Wales
Alex Callender is penalised at the breakdown again, which allows Japan to put the pressure on with another driving line-out.
That is followed by hard carries but this time Kate Williams gets it right at the contact area.
The flanker wins a releasing penalty five metres from her own line.
Excellent work.
Japan 5-14 Wales
Ceri Coleman-Phillips
BBC Sport Wales rugby reporter
This game is a huge opportuntiy for Lleucu George to show or remind Sean Lynn of her capabilities at fly-half.
Keira Bevan and Kayleigh Powell have both been preferred to her, but she's showing how well she can put Wales in the right areas with her kicking game.
She's also nailing her conversions, something she didn't manage last week.
Japan 5-14 Wales
Wales frustratingly get it wrong at the line-out.
They look to play off the top rather than going for the drive but Branwen Metcalfe's pass to Seren Lockwood is not on the money and it is knocked on, then Wales are pinged for offside.
Chance gone.
Japan 5-14 Wales
Japan play a bit too much in their own half and Wales get over the ball to win a penalty.
They kick back into the 22, where they will try to get another driving line-out going after Alex Callender has a cut seen to.
Japan 5-14 Wales
Siwan Lillicrap
Former Wales captain on BBC Radio Wales
That's a good drill from the Welsh forwards.
It was a good, patient set-up from the line-out and Kelsey Jones doesn't go too early.
Kelsey Jones (Lleucu George)
Watch as Kelsey Jones extends Wales' lead in Japan
Wales hooker Kelsey Jones matches the effort of her opposite number.
She hits the jumper at the front, then the pack stay patient to go over.
There is a quick check by the TMO for obstruction but the try is good, and Lleucu George then slots the conversion to stretch beyond a score.
Japan 5-7 Wales
Terrific kick by George puts Japan under pressure, and Wales then turn them over.
Penalty at the breakdown and Wales have a decision to make.
Scrum? Nope, to the corner...
Japan 5-7 Wales
Philippa Tuttiett
Former Wales international on BBC One Wales
The WXV has been created to make sure nations are getting more international fixtures.
England have played over 350 international Test matches whereas Japan have only played 100, yet they both played in the inaugural World Cup in 1991.
It just shows the disparity in experience.
Japan 5-7 Wales
Conditions are much better for handling today but it's been a bit scrappy so far.
Wales are looking to get width on the ball but haven't been their slickest yet.
Japan seem to be pretty organised in defence.
Japan 5-7 Wales
Philippa Tuttiett
Former Wales international on BBC One Wales
It's interesting to see that Alex Callender has been moved to eight in order to get Bethan Lewis on the field.
It's a brilliant option for Sean Lynn to play with, and don't surprised to see them inter changing throughout the game.
Japan 5-7 Wales
Siwan Lillicrap
Former Wales captain on BBC One Wales
That's such a well-drilled driving maul from Japan.
Their patience, their height, their connections in that maul are all spot on, it will be a really hard weapon to stop.
Moe Nagaoka
Watch as hooker Moe Nagaoka scores Japan's first try
Wales pay the price for not clearing their lines.
Discipline is costly and the drive goes over, with hooker Moe Nagaoka the scorer.
Japan were nilled last week but have their first points, and they deserve them.
The conversion is wide.
Japan 0-7 Wales
Japan back up errors. Knock on and then a scrum penalty.
Not the best clearance by Lleucu George and that is followed by a wonky line-out.
Wales fail to clear their lines... and it's followed by a penalty at the resulting Japan line-out.
