Sena is usually wearing the classic suit and tie, which is similar to Takeru's style or his willwear. He has a cleanly cut ash brown hairstyle with hints of gray, blue eyes, and a light-fair skin tone.
Sena is very serious and profesional. He has described himself as "a person who separates trash". He is shown getting annoyed at Takeru at times (especially when Takeru throws him during missions), but usually tolerates him.