First thing to know about Nananin no ayakashi: this characters and their personalities were created for a seiyuu variety show called "Seiyū Danshi desu ga...?" thw show itself was created to test the abilities of the 7 seiyuus.
This short anime is basically funny stories with the ayakashis, silly games etc. So I'll recommend this if you either like chibi things or are fan of the seiyuus.
Yūto Uemura: It appears in the program under the nickname of Mut-chan. His color is blue and his character is Meiteimu, an inugami who loves green tea donuts.
Yūichirō Umehara: His nickname is Ume-chan. His color is violet and
his character is Guden, a tengu known for being the king of trivialities.
Keisuke Kōmoto: His nickname is Kō. His color is dark green and his character is Kurokitenko, a black kitsune who loves books.
Yūsuke Kobayashi: His nickname is Bayashi. His color is red and his character is Yū, a kind zashiki-warashi who never separates from his wrist.
Yūsuke Shirai: His nickname is Shiraimu. His color is yellow and his character is Shirō, a somewhat mean white kitsune who likes to play jokes.
Yūtarō Honjō: His nickname is Pon-chan. His color is light green and his character is Pontaro, a docile tanuki and loved by all.
Kazutomi Yamamoto: His nickname is Kazū. His color is pink and his character is Cheruta, a Nekomata who speaks with a Kansai dialect and is an avid consumer of milk tea.
Jun'ichi Suwabe as Andrew, a carpet tiger who acts as the show's narrator. It also becomes a small plush tiger according to the scene.
Btw, all of the seiyuus created their characters.