About us

C.T.S 株式会社 (CTS Co., Ltd.) is a Japan-registered telecommunications company providing SIM cards, eSIM, Pocket WiFi, and Home WiFi services for foreigners in Japan. Headquartered in Kawaguchi, Saitama, we have served 10,000+ international customers since 2019.

We are an official partner of Japan's leading mobile network operators — SoftBank, NTT Docomo, Rakuten Mobile, and KDDI au — providing direct network access with no third-party routing.

What We Offer

  • eSIM — Instant QR code activation, plans from 1 day to monthly. From ¥500. Browse eSIM →
  • Data SIM — Physical SIM, 1GB to unlimited, no contract. From ¥460/month. Browse Data SIM →
  • Voice SIM — Japanese phone number + data + calls. From ¥980/month. Browse Voice SIM →
  • Pocket WiFi — Portable router, 10+ devices, unlimited data. From ¥4,800/month. Browse WiFi →
  • Home WiFi — 5G home internet, 30 devices, plug & play. From ¥5,200/month.

Why 10,000+ Customers Choose C.T.S

  • Japan-registered company — Corporate number 0400-01-110329, Telecom license A-01-17459
  • Multilingual support — English, Vietnamese, Indonesian, Burmese, Thai, Japanese
  • No contract — Prepaid monthly plans, cancel anytime
  • Free shipping — Across all of Japan
  • Flexible payment — Credit cards, SmartPit, PayPay, LINE Pay, bank transfer

Connect With Us

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C.T.S 株式会社 Japan Office

会社概要

社名 ：C.T.S株式会社

電気通信事業法 届出番号：A-01-17459

古物商許可証：埼玉県公安委員会 第431030070084号

設立 : 令和01年０８月05日

役員 : 代表取締役 グエン クオツク タオ （鈴木 タオ）

資本金 ：500万円

住所 ：本社 〒332-0034 埼玉県川口市並木２丁目４１−９ 九龍ビル４０１号

事業内容 ：格安SIM・音声販売

POCKET WIFI 販売

引っ越しサービス

中古PC・中古スマートフォン販売

従業員数 : 8名(2022年10月現在)

主要取引銀行：楽天銀行

TEL-FAX : 048-278-4612

EMAIL : kanri@cts-world.jp