The youngest member of the team of officers trying to track down Kira. Sometimes his naivity can get the better of him and he often places himself in huge danger because of his actions
Matsuda is often outspoken in the group; he always tries to offer his assistance, often without telling the group and putting his life at risk. He takes a liking to Light and is also a fan of Misa, as he is upset when he has to fake his death and cannot be her manager anymore.
Matsuda is very simple and quite an average man, he often thinks on his feet and makes decisions very quickly and is quick to voice his opinions on the Kira case. He also often wonders whether or not Kira is doing the right thing or not by killing criminals. He is also very good friends with Soichiro Yagami and is often shown speaking to him.
When Light is revealed as Kira at Yellowbox Warehouse, Matsuda is the most shocked of the team. He has always liked Light and is outraged to learn that he had been fooled; he is particularly upset, asserting that Light's actions had led to the death of Soichiro. Matsuda succeeds in saving Near's life by shooting Light's hand, causing him to drop the pen that he was writing Near's name with. Matsuda shoots him several more times to stop Light from writing Near's name in his own blood. The enraged Matsuda nearly kills Light with a shot to the head, but he is stopped by the rest of the Japanese investigation team.