Keiko Arahida has a tattoo of the Japanese kanji 信 (meaning "believe"; romaji: shin) on her left wrist. This tattoo is the title image of episode 1.09 "Believe".
Arahida gets the tattoo after seeing it on her wrist in her flashforward, in which she is in love with and meets Bryce Varley. ("Believe")
After Arahida is arrested by ICE and put into an immigration detention facility in Lancaster, Teek warns Arahida that she could spend up to a year in detention, but noticing her believe tattoo, said that Arahida should continue believing. ("Countdown")