IIreland opened their World Cup campaign with a six-try victory over Japan in an impressive display at Franklin's Gardens.
Eight years on from their last appearance at a World Cup finals, this was an early statement of intent from Ireland with six different try scorers in Northampton.
Amee-Leigh Costigan, Neve Jones, Beibhinn Parsons and Fiona Tuite had the bonus point wrapped up before half-time with further second-half tries from Eve Higgins and Enya Breen.
All six were converted by Dannah O'Brien.
Japan scored a try in each half from Haruka Hirotsu and Masami Kawamura before Ireland lost prop Linda Djougang to the sin-bin late on.
Ireland play Spain in a second Pool C game next Sunday before a potential pool decider against New Zealand in two weeks' time.
