Hur to get 126 buddy hearts per day!
If you make your buddy excited (without a poffin), you can probably get between 14 and 24 hearts in what might take around four hours without switching buddies in between, even though you only need to interact once every half hour. You can probably repeat this 3 times per day, so let's say 42–70 hearts per day.
If instead you give your buddy 6 hearts (feed, play, snapshot, battle × 3), switch buddy, and repeat 20 times, you can get 126 hearts per day! According to my video below, it takes about two and a half minutes per buddy. You could probably push it down to 2 minutes if you really focus. However, it still takes 42–52 minutes in total, so I rarely do all 20 switches myself! If you walk routes, you can switch buddy after each route for an extra heart. If you explore new places, you can switch buddy after every new PokéStop or gym you spin.
Bonus hearts (gift, souvenir) are not included above.
Details on how to give your buddy 6 hearts in less than two and a half minutes:
- Feed: give a Golden Razz Berry (fastest) or three other berries (for example regular Razz Berries)
- Play: rub your buddy’s cheek until you get the correct reaction
- Snapshot: take a photo of your buddy (tip: disable “AR Buddy” in the app settings), and you do not need to save the photo
- Battle × 3: do trainer battles with Blanche, Candela, or Spark three times. Leave the battle as soon as possible after it starts, you still get the heart.
I demonstrate this in the video below, where I also happen to get a souvenir.
As we say in the IT industry: Nine women cannot make a baby in one month. There is also an extension to that saying: Nine women can make nine babies in nine months.