Delivery Reports
Unfortunately, delivery reports from Japanese numbers are unreliable and can be fake.
URLs
It is not allowed to send URLs in your messages. Messages that contain a weblink are classified as illegal and are either discarded completely or a part of the illegal text will be removed.
Operator-Specific Restrictions
DoCoMo A maximum of 160 bytes/160 standard characters per SMS applies
Softbank A maximum of 160 bytes/160 standard characters per SMS applies
KDDI A maximum of 100 bytes/100 standard characters per SMS applies