Please tell me the book you recommend

Hello! I’m japanesekawaiigirl. I was wondering if anyone could recommend a book that fits the following criteria: 1.Mystery or adventure 2.A buddy dynamic (a trio or group of four is totally fine too!) 3.Not too scary 4.Fun, witty dialogue between the characters 5.Set in modern-day Britain 6.Adult protagonists 7.A warm, feel-good atmosphere would be a [...]