J. Koyanagi is a games designer. Koyanagi has been working with Konami Digital Entertainment, Hudson Soft and Now Production. Koyanagi started in 1991 as the designer of Adventure Island II (1991). Then, J. Koyanagi went on to work on Adventure Island III (1992) as the designer. The latest work of J. Koyanagi was Adventure Island II (3DS), published in 2014.