I stumbled over an older site that lists the Shift-JIS codes and images for -mode and (then Vodafone, now Softbank) emojis around the year 2000. It also has a list of ASTEL emojis that I haven't ever heard of before. Their brand seems to have been ASTEL dot i. They are black and white, but include some entries that are still not available in Unicode.

Emojis seem to have been animated by switching character codes:

Specific References

• ?
• emojis
• Qvarie: ASTEL

Standard References

• Unicode Technical Standard 51 “Unicode Emoji” (beta)
• How to propose emojis to Unicode
• How to propose other additions or changes to Unicode (required form, email address: docsubmit＠unicode.org)
• Unicode document submission form