Keith Earls, Dan Leavy and Jack Conan all scored double for Ireland as they completed a 22-50 convincing win over Japan at Shizuoka Stadium on Saturday.
Will Jordan and Caleb Clarke scored a hat-trick each as New Zealand registered a 3-69 bonus point victory over Ireland in the U20 Championship 2017 encounter at AIA Arena on Thursday.
Scotland made amends for their defeat against New Zealand as they completed a 28-32 win over Ireland in a closely contested U20 Championship encounter at AIA Arena on Sunday.
Fullback Massimo Cioffi scored the decisive converted try as Italy went on to beat Ireland by 21-20 in a thrilling World Rugby U20 Championship encounter on Wednesday at AIA Arena.
Former Ireland captain Brian O'Driscoll has backed Munster lock Donnacha Ryan to be selected for the British and Irish Lions squad for the 10-game tour of New Zealand in June.
Irish Rugby Football Union's chief executive Philip Browne is confident that Ireland's history of not hosting a World Cup previously will work in their favour during the bid on the 2023 edition of the tournament.
Six Nations 2017 tournament came to an end with England retaining the title but their Grand Slam hopes dashed with their defeat to Ireland in the final round of the tournament.