- 骨の折れる仕事｛しごと｝
- on the undertaking that: （that 以下）という条件｛じょうけん｝で、（that 以下）という約束｛やくそく｝で
- undertaking: undertaking n. 計画, 事業, 企て, 仕事; 約束.【動詞＋】The government was forced to abandon the undertaking because it became clear that it would cost more money than had been expected.政府は予想より多額の金がかかることが明らかになったのでその
- in tough: 苦労｛くろう｝をして、困難｛こんなん｝に立ち向かって
