Tamagotchi iD - Tamatomo

The English meaning for Tamatomo is Tamabuddy.
On the Tamagotchi iD, the Degree of Friendship bar has initially one coloured segment. After your Tamagotchi iD character has become an adult, the bar can be extended by up to four more coloured segments. (For a total of five segments.) A coloured segment is added for each of the four Japanese letters, Ta, Ma, To, Mo that you earn. You can earn these letters by performing certain actions with your Tamagotchi iD character. Sometimes there is more than one way to earn a letter.

Once you've collected all four letters, you get the friend stamp for your current character. (Duplicate stamps will not be issued.)

If {all four letters are lit up} and {at least some of the right-most coloured segment of the friendship bar is filled in} and {you have at least two friend stamps} then your character can travel to Friends Plaza, and meet other previous friends you've raised. Also, there will be a special surprize outside your Tamagotchi home when {you have at least five friend stamps}!

The actions you have to perform to earn the Ta, Ma, To, Mo letters are different for each Tamagotchi iD character. 

Mametchi
Ta - eat Hamburger Steak (Restaurant)
Ma - eat MameDaifuku (Cafe)
To - wear the Baseball Cap (Accessory Shop) / read the Encyclopedia (TamaDepa)
Mo - keep your character for 72 hours after he becomes an adult

Kuromametchi
Ta - eat Yakisoba (Convenience Store)
Ma - eat Popcorn (Cafe)
To - wear Headphones (Accessory Shop) / play with Soccer Ball (connection gift)
Mo - keep your character for 72 hours after he becomes an adult

Gozarutchi
Ta - eat Norimaki (Convenience Store)
Ma - eat Osenbei (Cafe)
To - play with Shuriken Throwing Star (TamaDepa)
Mo - keep your character for 72 hours after he becomes an adult

Kuchipatchi
Ta - eat Pizza (Restaurant)
Ma - eat Pancakes (Cafe) / eat Mixed Soft icecream cone (Cafe via connection gift)
To - wear Chef's Hat (Accessory Shop)
Mo - keep your character for 72 hours after he becomes an adult

Kikitchi
Ta - eat Unajyu (Restaurant)
Ma - drink Banana Juice (Cafe)
To - play with Remote Control Car (TamaDepa) / wear Cowboy Hat (connection gift)
Mo - keep your character for 72 hours after he becomes an adult

Lovelitchi
Ta - eat Napolitan A.K.A spaghetti (Restaurant)
Ma - eat Heart Cake (Cafe)
To - wear the Heart Sunglasses (Accessory Shop) / play with the Stage & Microphone (TamaDepa after password)
Mo - keep your character for 72 hours after she becomes an adult

Chamametchi
Ta - eat Omurice (Restaurant)
Ma - eat Ichigo Doughnut (TamaDoughnuts) / drink Cream Soda (connection gift)
To - use Picture Book (TamaDepa)
Mo - keep your character for 72 hours after she becomes an adult

Makiko
Ta - eat French Toast (Restaurant)
Ma - eat Cupcake (Cafe)
To - play with Tennis Racket (TamaDepa) / wear Elegant Hat (connection gift)
Mo - keep your character for 72 hours after she becomes an adult

Memetchi
Ta - eat Chocolate Cornet (Convenience Store)
Ma - eat French Cruller (TamaDoughnuts) / eat Roll Cake (Cafe via connection gift)
To - play with Kirakira Stenciling (TamaDepa)
Mo - keep your character for 72 hours after she becomes an adult

Flowertchi (Furawatchi)
Ta - eat Sandwich (Convenience Store)
Ma - eat Macaron (Cafe)
To - play with Hula Hoop (TamaDepa) / wear Headdress (connection gift)
Mo - keep your character for 72 hours after she becomes an adult

Uwasatchi
Ta - eat Anpan (Convenience Store)
Ma - eat MameDaifuku (Cafe) / eat An Doughnut (TamaDoughnuts)
To - wear the Star Antennas (Accessory Shop) / use the Transceiver (connection gift)
Mo - keep your character for 72 hours after she becomes an adult


Source: tamatomo