That depend of the song/PV you saw. You know, vocaloids (at least the official ones) doesn't have an specific personality or relationship. I will give you one of the songs that Gumi and Len sings: ah wonderful nyan life(I think that's the name). That shows Gumi and Len. You can look it up on youtube. Anyway, some songs don't show Gumi and Len. So I gave you the answer. Hope you understand. :)
I love all Len songs but my resources and votes say Servant of evil and Spice are the most popular.
The cast of Love Letter - 2011 includes: Marvelous Alejo as Len
Well, since I'm into LenxMiku, I guess he is.
no she does not miku is usually paried with kaito and other boys like len
The cast of A Moment of Love - 2005 includes: Loh Bok Lai Amy Len
The cast of The Language of Love - 2006 includes: Alex Dee as Len Katie Pattinson as Sue
Love in old-time stories was often portrayed through acts of chivalry, sacrifice, and devotion between characters. These stories emphasized courtly love, forbidden romances, and the overcoming of obstacles to be together. Themes of eternal love and loyalty were common in classic tales from different cultures and time periods.
Len Marino goes by Len.
Yes he does with all of his herat and never lets any one hurt her
Miku doesn't really like Katio. Kaito already likes Meiko so there's no point for Miku to love him. SHE LOVES LEN
The cast of Things We Do When We Fall in Love - 2007 includes: Loh Bok Lai Len Siew Mee