Natasja Behan and Katie O'Dwyer scored Ireland's tries, but the visitors were a distant second in the contest.

Japan's attentions now turn to this autumn's World Cup in New Zealand.

While Ireland will be disappointed by their showing, particularly in the context of how impressive they were the week before, head coach Greg McWilliams will hope his young players have benefited from exposure to Test rugby in what was the women's team's first-ever summer tour.

After a scintillating display in the first Test in Shizuoka, Ireland picked up where they left off in humid conditions at Prince Chichibu Memorial Stadium, scoring the opening try inside three minutes.

Ailsa Hughes plucked the ball from a maul and attacked the short-side before feeding Behan, who crossed for her first international try on her second appearance.

Natasja Behan scored her first international try inside three minutes

The lightning-fast start would prove to be as good as it got for the Irish, as their struggles at the set-piece handed Japan the advantage in both territory and possession.

The Irish defence initially did well to repel the hosts' attacks, twice holding them up over the line after Japan found momentum through a driving maul.

However the Japanese pressure did eventually pay off as they played the ball quickly from the back of a scrum to fly-half Otsuka, who darted through a gap outside Enya Breen to level the scores.

The hosts hit the front four minutes before the break, again profiting from a solid scrum to set up a strike-play that saw Otsuka play an inside ball to Matsuda, who powered through Edel McMahon's attempted tackle to give Japan a deserved half-time lead.

The momentum was completely with Japan and Ireland could not apply enough sustained pressure to work their way back into the contest, instead coughing up more territory after the break with Hinano Nagura adding her side's third try in the corner having collected Otsuka's skip-pass.

Three minutes later Matsuda realistically ended Irish hopes of a comeback as she stormed down the left, fending off poor tackles from Behan and Meabh Deely to extend Japan's lead to 17.

There was some brief respite for Ireland as they finally moved into the 22 themselves, mauling over the line with O'Dwyer touching down just before the hour mark.

However the score did nothing to fluster Japan, who kept coming with their powerful ball-carriers making ground with every carry, punching holes in the Irish line and creating space for Sachito Kato to burrow over for the hosts' fifth and final score.

Ireland: Deely; Behan, Dalton, Breen, Doyle; O'Brien, Hughes; Feely, Jones, Djougang; Fryday (capt), O'Connor; Brown, McMahon, Moore

Replacements: Hooban, Pearse, O'Dwyer, Schultzer, Keating, Scuffil-McCabe, Tilly.

Japan: Matsuda; Nagura, Furuta, Nakayama, Imakugi; Otsuka, Abe; Minami (capt), Nagata, Sadaka; Y Sato, Takano; S Sato, Nagata, Nagai.

Replacements: Lavemai, Taniguchi, Kato, Tamai, Yoshimura, Tsukui, Yamamoto, Hosokawa.