Formal to Client
Workplace · Email
このたびはご契約をいただきまして、誠にありがとうございます。精一杯努めてまいります。 — Thank you sincerely for entering into this contract with us. We will give it our very best effort. (Workplace · Email, Formal to Client, JLPT N2)
You
このたびはご契約をいただきまして、誠にありがとうございます。精一杯努めてまいります。
このたびはごけいやくをいただきまして、まことにありがとうございます。せいいっぱいつとめてまいります。
Thank you sincerely for entering into this contract with us. We will give it our very best effort.
Romaji: Konotabi wa gokeiryaku wo itadakimashite, makoto ni arigatou gozaimasu. Seiiccupai tsutomete mairimasu. / Reply Romaji: Douzo yoroshiku onegai itashimasu.
Reply
どうぞよろしくお願いいたします。
どうぞよろしくおねがいいたします。
We look forward to working with you.
Gesture & etiquette
This is a written (email) communication. Send promptly after deal confirmation. Keep the email warm but concise — one paragraph of gratitude, one commitment statement. If a superior reviewed and approved the contract, CC them on this thank-you email. Follow up with a kickoff meeting request in the same email or a separate one sent immediately after.
The phrase 'seiiccupai tsutomete mairimasu' (we will work with all our effort / do our absolute best) is the standard professional commitment phrase after a contract is signed. It uses the humble 'mairu' and signals dedicated effort. Sending this email within the same business day as the contract signing is considered a mark of professionalism in Japanese business relationships.