If you don't already know, one of the best ways to earn EXP in Yakuza 6 is by keeping Kiryu properly fed. However, what you might not know is that most restaurants found in both Kamurucho and Onimichi have secret menu Combinations, the same that will see you obtain Bonus EXP for combining said items of Food. By eating these menu combinations at said establishments when Kiryu is hungry, you will earn loads of EXP in no time at all! But also be warned: you won't receive any Bonus EXP if Kiryu's Hunger Gauge is already full, even if you Eat the proper food combination.
Kamurucho Secret Menu Combinations (Restaurants & Combos)
Akaushimaru: Beef Plate + Draft Beer
Bantam: The Macallan 30 Years Old + Hibiki 30 Years Old + Ballentine's 30 Years Old
Cafe Alps: Chocolate Parfait + Sandwich Set
Fuji Soba: Soba (any) + Katsudon
Fuji Soba: Katsudon + Curry Rice
Gindaco Highball Tavern: Absolutely Tasty Takoyaki + The Kaku Highball
Ikinari Steak: Wild Steak (300g) + Wild Hamburg Steak (300g)
Ikinari Steak: Tenderloin Steak (200g) + Salad + Soup
Kanrai: Salted Tongue + Kalbi + Sirloin
Kanrai: Kanrai Special Salad + Kimchi Combo + Stone-cooked Bibimbap
Kyushu No.1 Star: Kyushu Tonkotsu Ramen + Fried Rice + Gyoza
M SIDE Cafe: Croissant + Toast + Special Bread
Osaka King: Mapo Tofu + Sichuan Dandan Noodles + Shrimp in Chili Sauce
Osaka King: Mixed Fried Rice + Original Fried Gyoza + Ramen
Quadra Garden: Chocolate Cake + Cheesecake
Ringer Hut: Vegetable Champon + Vegetable Saraudon + Veggie-filled Soup
Smile Burger: Smile Burger + Smile Fries + Smile Shake
Smile Burger: Tuna Burger + Smile Salad
Sushi Gin: Kiwami Set + Kiwami Chirashi + Kiwami Seafood Bowl
Sushi Zanmai: Special Bluefin Tuna Bowl + Tuna Zanmai
Wette Kitchen: Onion Ring + Tomato Onion Soup
Wild Jackson: Wild Burger + Wild Fried Chicken
Yoronotaki: Draft Beer + Edamame
Yoronotaki: Sashimi Platter (3pcs) + Kotchori Salad + Juicy Mince Cutlet