What does 開いた本 look like on DoCoMo?

On DoCoMo it is the design shipped in 2013, shown above at full size. Older revisions are listed beneath it.

When did DoCoMo add 開いた本?

DoCoMo first drew 開いた本 in 1999, released 1999年1月1日.

NTT DoCoMo has shipped 6 versions of 開いた本. Each is dated, so you can see when the design changed.

DoCoMo

NTT DoCoMo has drawn 開いた本 6 times. Every revision DoCoMo has shipped is below, newest first.

What does 開いた本 look like on DoCoMo?: On DoCoMo it is the design shipped in 2013, shown above at full size. Older revisions are listed beneath it.
When did DoCoMo add 開いた本?: DoCoMo first drew 開いた本 in 1999, released 1999年1月1日.
How many times has DoCoMo redrawn 開いた本?: NTT DoCoMo has shipped 6 versions of 開いた本. Each is dated, so you can see when the design changed.

DoCoMo artwork for this emoji spans 1999 to 2013.