When classes start this September, more than 100 extra guidance counselors and social workers will stream into some of New York City’s most fragile schools.

They are all part of the education department’s Single Shepherd program, and their job description is as simple as it is daunting.

“Your job will be: Whatever it takes,” New York City schools Chancellor Carmen Fariña told them at a training on Tuesday. “You may have to do something a little different. You may have to go a little out of the way.”

The $15 million program pairs each student with a caring adult who will follow him or her through middle school and high school, hopefully clearing the way for college. That may mean collecting winter boots for a needy child, planning a pizza party to celebrate good behavior, or figuring out why a student is always late to class.

“We can’t separate our students from their home lives. We can’t separate students from their neighborhoods,” Fariña said. “Your job is all encompassing.”

The program will be piloted in the South Bronx’s District 7 and Brooklyn’s District 23, two districts that have among the lowest graduation rates in the city. Every middle and high school student in those districts will work one-on-one with a social worker or counselor until they graduate.

The department was flooded with 1,000 applications for about 130 openings for guidance counselors and social workers to work in the program. At least 110 have already been hired.

The shepherds will serve 16,000 students, for a ratio of one adult per 100 kids. Though that may seem like a heavy load, it’s well below national recommendations. The American School Counselor Association recommends a ratio of 1 counselor per 250 students.

With just a few weeks before school starts, some of the program’s details aren’t firmed up yet.

For example, it’s unclear what will happen to students if they transfer to a new school — an issue that could prove especially relevant in District 23, which has one of the highest percentages of homeless students in the city.

Shepherds will be assigned to individual schools, but their day-to-day routines — how often they’ll meet with students, for example — are still being worked out.

“We’re working on all that right now, what the model’s going to look like, once everyone gets into schools,” said Chrisanne Petrone, program manager for Single Shepherd. “Everyone is just coming on board. The excitement is high.”