Ryan Elias returns at hooker, while Seb Davies comes into the side at blindside flanker. Tom Phillips moves to No 8 with Harrison Keddie ruled out with a shoulder injury. The only change in the backs sees Elis-Wyn Benham make his first appearance in the tournament on the right wing.
Coach co-ordinator Allan Lewis said, “We have reviewed the England game, looked at our defensive weaknesses in the first 30 minutes especially and how to improve them. It is time to move on to the Japan game now, and we are certainly not taking them lightly.
“They pose a threat, especially with the ball in hand, they attack from anywhere so it is vital we concentrate on producing a good performance that secures a win first and foremost. If we manage that and to score some tries, we will look at bonus points and points difference but we must get that win first.
“The changes in the 23, with Torin Myhill, Lee Taylor and Joe Thomas coming onto the bench, ensure all our squad members will have been part of a matchday 23 at the Pool stage.”
Wales Under 20 v Japan (Viadana, Wednesday 10 June, 5.30pm UK time, S4C):
Dafydd Howells (Ospreys/ Neath); Elis-Wyn Benham (Blues/ Cardiff), Garyn Smith (Blues/ Pontypridd), Owen Watkin (Ospreys/ Bridgend), Joshua Adams (Scarlets/ Llanelli); Jarrod Evans (Blues/ Pontypridd), Tomos Williams (Blues/ Pontypridd); Luke Garrett (Dragons/ Cross Keys), Ryan Elias (Scarlets/ Carmarthen), Dillon Lewis (Blues/ Pontypridd), Adam Beard (Ospreys/ Aberavon), Rory Thornton (captain, Ospreys/ Bridgend), Seb Davies (Blues/ Pontypridd), Ollie Griffiths (Dragons/ Newport), Tom Phillips (Scarlets/ Llanelli)
Replacements: Torin Myhill (Scarlets/ Llanelli), Keagan Bale (Dragons/ Cross Keys), Joe Jones (Blues/ Cardiff), Lee Taylor (Carmarthen Quins), Liam Belcher (Blues/ Pontypridd), Kieran Hardy (Scarlets/ Carmarthen), Daniel Jones (Scarlets/ Carmarthen), Joe Thomas (Ospreys/ Swansea)
