Invisible Man & His Soon To Be Wife Vol 4

Tounome, the kind and dapper invisible detective, and Yakou, the shy and bashful woman, are as lovey-dovey a couple as it gets. Between clumsily asking for kisses and sleeping over after a long day at work, Yakou has kept the butterflies in her stomach plenty busy, but Tounome seems like he's getting cold feet... Will a heart-to-heart clear the way for them to travel through life together, or will it force them to part?!