In recent years, the acoustic guitar duo Gontiti（ゴンチチ）has probably become known among anime fans for their work on the score for the relaxing "Amanchu!"（あまんちゅ！）and "Amanchu! Advance"（あまんちゅ！〜あどばんす〜）. My anime buddy might have the soundtrack, and if so, he could probably use it for relaxation purposes. In fact, I would highly recommend getting a hammock just for those purposes.
Back in early 2016, I wrote about PSY-S' collaborative 1987 album "Collection" and lamented that I couldn't feature a full version of one of my favourite tracks on that release by Gontiti themselves. Well, I'm no longer lamenting. About a good 30 years before Masahiko "Gonzalez" Mikami（三上雅彦）and Masahide "Titi" Matsumura（松村正秀）wove their wonderful feel-good music about a couple of high school divers, they contributed to "Collection" with "Honto no Uso" (True Lies).
As I mentioned in the article for the original album, while Gontiti created "Honto no Uso", PSY-S' Masaya Matsuura（松浦雅也）arranged it and vocalist CHAKA added some of her vocals. It's some lovely relaxing bossa nova with some of those Matsuura synths thrown in for good measure. I especially love that one part in there when the duo go into a brief exploratory instrumental with their guitars.