Konami calls Tegami Bachi: Kokoro Tsumugu Mono an adventure RPG, but the combat screenshot looks more like a console RPG. Maybe, something like classic Phantasy Star. The system is said to have simple commands and players can adjust the timing of Lag’s heart bullets in battle. Instead of an overworld, players move on a board game-like world map.
After each successful package delivery, Lag gets tougher missions and a chance to grow. He can become a postmaster type or guardian type and each type changes the story in some way.