A first summer tour of its kind for Irish women's rugby, and the first of a two-Test series against Japan.
After a difficult Six Nations campaign which finished on a high, Greg McWilliams brings his side to the far east where they face a Japanese group that are finding good form ahead of the World Cup in October.
Ireland may be ranked six places higher than the hosts in the world rankings, but the odds will likely be stacked on the side of Japan, who have won four of their last five Tests in recent months.
With a full squad, Ireland would certainly have too much for the Shakura Fifteen, but several injuries, as well as the upcoming Sevens World Cup means that 10 of the 29 players in the full Irish squad are uncapped.
As such, the Test series is likely to be an experimental one for Ireland, who are testing out various combinations, particularly in their backline, as they look to get a head start on others for the next World Cup cycle.
The game gets underway at 7pm local time, which is 11am in Ireland.
TG4 will have live coverage of the game at Ecopa Stadium, getting under way from 10.40am.
RTE.ie/sport and the RTÉ News app will have have a live blog of the game, as well as a match report and post match reaction.
Even with kickoff at 7pm, conditions are expected to be hot and humid in Shizuoka, with temperatures close to 30C, and humidity between 85 and 90%.
Head coach Greg McWilliams has named an experimental backline for the first game on tour, with four debutants behind the pack.
Eighteen-year-old Dannah O'Brien starts at out-half, where she's partnered by Ailsa Hughes, while another teenage debutant Aoife Dalton comes into the centre, joining Enya Breen in midfield.
There are also two new caps in the back three, with Blackrock and Leinster wing Natasja Behan included in the 14 shirt, with her clubmate Méabh Deely named at full-back.
Aoife Doyle completes the backline on the left wing, to earn her 11th cap.
In the pack, Greg McWilliams has gone with seven of the eight forwards who began their most recent outing against Scotland in April.
The only change sees Katie O'Dwyer start at tighthead, with Christy Haney dropping to the bench. O'Dwyer is joined in the front row by Neve Jones and Linda Djougang.
As usual, captain Nichola Fryday is joined at lock by Sam Monaghan, who recently completed a move from Wasps to Gloucester-Hartpury in the Allianz Premier 15s.
Hannah O'Connor starts at number 8, in between flankers Edel McMahon and Dorothy Wall.
For Japan, Saki Minami captains the side on her 24th test, while there are recalls for Kyoko Hosokawa at openside flanker and scrum-half Moe Tsukui, both of whom last played for the Sakura Fifteen in their 10-12 victory over Australia in May.
Japan: Ria Anoku; Riho Kurogi, Rinka Matsuda, Shione Nakayama, Komachi Imakugi; Ayasa Otsuka, Moe Tsukui; Saki Minami (capt), Nijiho Nagata, Yuka Sadaka; Kie Tamai, Maki Takano; Misaki Suzuki, Kyoko Hosokawa, Ayano Nagai
Replacements: Hinata Komaki, Kotomi Taniguchi, Makoto Lavemai, Masami Kawamura, Seina Saito, Megumi Abe, Minori Yamamoto, Sakurako Korai
Ireland: Méabh Deely; Natasja Behan, Aoife Dalton, Enya Breen, Aoife Doyle; Dannah O'Brien, Ailsa Hughes; Linda Djougang, Neve Jones, Katie O'Dwyer; Nichola Fryday (capt), Sam Monaghan; Dorothy Wall, Edel McMahon, Hannah O'Connor.
Replacements: Emma Hooban, Chloe Pearse, Christy Haney, Taryn Schultzer, Grace Moore, Nicole Cronin, Leah Tarpey, Molly Scuffil-McCabe
Greg McWilliams (Ireland head coach): "I'm just so excited to see how they cope. If they cope well, that's a real bonus. If they don't, it's our job as a management team to be able to sit down with them and talk them through the performance and let them know areas that they'll need to get better at."
Nichola Fryday (Ireland captain): "You can't underestimate the players in our squad. We have seriously talented players, like the younger girls coming through have shown what kind of flair they have. And then you have the likes of Sam [Monaghan] and Linda [Djougang] who thrive off unstructured play."
Ireland 15-12 Japan (20 November 2021)
Ciara Griffin has done it again! Try number two, after a TMO review, and Ireland are in front. pic.twitter.com/Hjrll6yaM8— RTÉ Rugby (@RTErugby) November 20, 2021
In difficult conditions at the RDS, Ireland came from 12-3 down with a player less to record a 15-12 win.
Having seen Hannah O'Connor red-carded for a dangerous tackle in the first half, Ireland struggled at times in the opening half, conceding two tries to the Shakura Fifteen.
However, in her final game before retirement, captain Ciara Griffin scored twice in the second half to drag her team over the line and sign off her Test career with victory.