NTT Docomo Inc., Japan's largest mobile-phone carrier by subscribers, plans to move further into the content business to differentiate itself from rivals that offer similar pricing plans and phone models.

The wireless operator offers videos, including episodes of the Gundam anime series about giant robots, as well as music and books through its dmarket app. NTT Docomo is adding content to the service, which comes pre-installed on Apple Inc. iPhones and Android-based mobiles for subscribers.

NTT Docomo is seeking to boost revenue and profit as the population in its home market declines. The wireless carrier said in May it was on the hunt for deals worth as much ¥1 trillion ($9.6 billion) amid a search for growth overseas, a strategy on which Chief Financial Officer Hirotaka Sato declined to comment during an interview on Wednesday.