Wales lost to Australia (38-5) in their final Pool D game on Saturday after beating Tonga (51-5) and Canada (51-15) in their other Pool games. The defeat to Australia kept Wales out of the last four, but a win over Ireland tomorrow would place Wales in the top six in the final rankings.
Wales will play either France or Samoa in their final game on Sunday.
Glamorgan Wanderers and Blues academy prop Andrews replaces Simon Gardiner on the tight head, while there is a juggling of the back row with Ebbw Vale's Rhys Jenkins returning after a hamstring twinge on the open side, and Justin Tipuric, who has captained the side so far in the competition, moving to the blindside. Ebbw Vale's James Thomas retains his place in the back row but moves to no 8, with Rory Pitman starting on the bench.
Behind the scrum, Carmarthen Quins' Jason Harries replaces Scott Williams in the centre and Rhys Downes starts on the wing with Nick Reynolds sustaining an injury against Australia, and with Jamie Davies ruled out of the tournament.
Wales head coach Phil Davies said, "This is a fantastic challenge for the players. We want to finish the tournament as strongly as possible, and this is the type of challenge the players will relish. The stadium is superb, one of the best venues I have seen during my career, and the conditions will certainly suit a running style of rugby.
"It is great to have Scott back in the starting line -up as captain. He has worked extremely hard to regain full fitness and great credit goes to the medical and conditioning staff. Simon Gardiner has done a very good job at tight head throughout the tournament to date and deserves to keep his place in our match 22.
"James Leadbeater has also worked very hard to get back to fitness and takes up a place in the 22 for the first time tomorrow.
Behind the scrum, we have included James Led beater for the first time since we arrived in Japan, alongside Scott, he has worked very hard to regain full fitness.
"We are pleased Rhys Downes has accepted the challenge of playing out of position due to injuries. We are hoping Nick Reynolds will be fit for our final game on Sunday."
Wales team v Ireland (Wednesday, 9am UK time):
Daniel Newton (Scarlets academy/ Llanelli); Jamie Loxton (Blues academy / Glamorgan Wanderers), Jason Harries (Carmarthen Quins), Ashley Beck (vice-captain, Ospreys academy / Aberavon), Rhys Downes (Blues academy / Pontypridd); Matthew Jarvis (Ospreys academy / Neath), Lloyd Williams (Blues academy / Glamorgan Wanderers); Aaron Coundley (Dragons academy /Ebbw Vale), Rhys Williams (Blues academy / Pontypridd), Scott Andrews (capt, Blues Academy / Glamorgan Wanderers), James King (Ospreys academy / Aberavon), Ashley Sweet (Dragons academy / Cross Keys), Justin Tipuric (Ospreys academy / Aberavon), Rhys Jenkins (Dragons academy / Ebbw Vale), James Thomas (Dragons academy / Ebbw Vale)
Replacements: Craig Attwell (Dragons academy/ Newbridge), Simon Gardiner (Scarlets academy / Llanelli), Rory Pitman (Ospreys academy / Bridgend / Taranaki), Josh Navidi (Blues academy / Glamorgan Wanderers), James Leadbeater (Cross Keys), Dai Langdon (Dragons academy / Ebbw Vale), Scott Williams (Scarlets academy / Llanelli)
Wales Pool D fixtures (all at Best Amenity Stadium, Saga):
Wales 51-5 Tonga Friday 5 June
Wales 51-15 Canada, Tuesday 9 June
Wales 5 v 38 Australia, Saturday 13 June