Angel-San's apperance is a small ghost with a pointed head, standing atop a coin.
In the extra chapter of Rosario+Vampire Season 2, Ghosts+Vampire, Tsukune was asking Moka about how ghosts and monsters were different. Realizing that there were more questions than answers, Moka suggested summoning a ghost and ask it directly. They used a spiritual device called Angel-San (Not the Ghost), which included a coin and a letter chart that was used to call and communicate with ghosts. They both accidently placed their fingers on the coin at the same time, causing them to blush. Just then, Kurumu Kurono jabbed both of Tsukune's eyes with her fingers, and stated that they needed to take Angel-San seriously, or they will be cursed. She also stated that they needed people with a strong sense for ghosts, so she, Mizore Shirayuki and Yukari Sendo formed their own version of the Ghost Busters. But out of the three, none of them has a sense for ghosts, causing Moka to get angry at them. Now that they decided to help Tsukune summon Angel-San, he felt more reassured, but Moka became disappointed that it wasn't just her and Tsukune anymore. All of them tried summoning Angel-San, but to no avail. Tsukune thought it was just a super stition, until the coin moved. As the coin began to move, Yukari stated that it was automatism, and they were just imagining it moving, although she was terrified herself. As the coin moved around the chart, everyone watched as it stoped on each letter, until finally spelled "Fondle Kurumu's breasts." Moka accused Kurumu of moving the coin herself, but Mizore pointed out that it must be a command from Angel-San, and it's testing their loyalty, and if they fail they will be cursed. Kurumu didn't want anyone but Tsukune to fondle her breasts. She then later forced him to squeeze her chest, stating that she didn't want him to get cursed for not obeying Angel-San. The coin then started to move again, and spelled out "Make children with Mizore." No surprise, everyone suspected Mizore moved the coin on purpose. She denied it, but like Kurumu, doesn't mind as long as it's Tsukune. But refusing to let him make children with Mizore, Moka stopped it from going any further and told her to put her panties back on. Now convinced someone is moving the coin, Moka thought about how to figure out who the culprit is. Before she could put more thought into it, the coin moved again and spelled out "French Kiss Moka." After losing her patience, Moka tore up the letter chart screaming "We're cursed!! I'm cursed!! Cursed!!!" She then grabbed Tsukune's hand and made him take her rosary off, releasing Inner Moka. But much to everyone's surprise, she asked if anyone still wanted to kiss her. Still shocked from what happened, they answered no, fearing what she would do if they did try to kiss her. Angered by their response, she shouted "Know your place!" before beating them. As the coin slid across the floor, the spirit of Angel-San appeared and apologized for getting carried away with his orders.