YGEX just announced on their website that Daesung will have his own diary series on Big Bang’s Japanese mobile blog, BIGBANG☆WORLD* (bigbangworld.jp). Just like Seungri’s "Seung-chan’s Diary", Daesung will be updating VIPs in Japan through his diary called "To-san’s New Discovery"**.
*You can only subscribe to BIGBANG☆WORLD if you’re in Japan
**"To" comes from Daesung’s Japanese stage name D-LITE, which is pronounced as D-LAI-TO. "San" is an honorific used in Japan just like "chan".